What is "crab"

Crab \Crab\,

1. [Pro

2. from the same root as crab, n.] Sour; rough; austere.

   The crab vintage of the neighb'ring coast.
   --Dryden.

Crab \Crab\, v. i. (Naut.) To drift sidewise or to leeward, as a vessel.
--Ham. Nav. Encyc.

Crab \Crab\ (kr[a^]b), v. t.

1. To make sour or morose; to embitter. [Obs.]

   Sickness sours or crabs our nature.
   --Glanvill.

2. To beat with a crabstick. [Obs.]
   --J. Fletcher.

Crab \Crab\ (kr[a^]b), n. [AS. crabba; akin to D. krab, G. krabbe, krebs, Icel. krabbi, Sw. krabba, Dan. krabbe, and perh. to E. cramp. Cf. Crawfish.]

1. (Zo["o]l.) One of the brachyuran Crustacea. They are mostly marine, and usually have a broad, short body, covered with a strong shell or carapace. The abdomen is small and curled up beneath the body.

   Note: The name is applied to all the Brachyura, and to certain Anomura, as the hermit crabs. Formerly, it was sometimes applied to Crustacea in general. Many species are edible, the blue crab of the Atlantic coast being one of the most esteemed. The large European edible crab is Cancer padurus. Soft-shelled crabs are blue crabs that have recently cast their shells. See Cancer; also, Box crab, Fiddler crab, Hermit crab, Spider crab, etc., under Box, Fiddler. etc.

2. The zodiacal constellation Cancer.

3. [See Crab, a.] (Bot.) A crab apple; -- so named from its harsh taste.

   When roasted crabs hiss in the bowl, Then nightly sings the staring owl.
   --Shak.

4. A cudgel made of the wood of the crab tree; a crabstick. [Obs.]
   --Garrick.

5. (Mech.)

   1. A movable winch or windlass with powerful gearing, used with derricks, etc.

   2. A form of windlass, or geared capstan, for hauling ships into dock, etc.

   3. A machine used in ropewalks to stretch the yarn.

   4. A claw for anchoring a portable machine. Calling crab. (Zo["o]l.) See Fiddler., n., 2. Crab apple, a small, sour apple, of several kinds; also, the tree which bears it; as, the European crab apple ( Pyrus Malus var. sylvestris); the Siberian crab apple ( Pyrus baccata); and the American ( Pyrus coronaria). Crab grass. (Bot.)

      1. A grass ( Digitaria sanguinalis syn. Panicum sanguinalis); -- called also finger grass.

      2. A grass of the genus Eleusine ( Eleusine Indica); -- called also dog's-tail grass, wire grass, etc. Crab louse (Zo["o]l.), a species of louse ( Phthirius pubis), sometimes infesting the human body. Crab plover (Zo["o]l.), an Asiatic plover ( Dromas ardeola). Crab's eyes, or Crab's stones, masses of calcareous matter found, at certain seasons of the year, on either side of the stomach of the European crawfishes, and formerly used in medicine for absorbent and antacid purposes; the gastroliths. Crab spider (Zo["o]l.), one of a group of spiders ( Laterigrad[ae]); -- called because they can run backwards or sideways like a crab. Crab tree, the tree that bears crab applies. Crab wood, a light cabinet wood obtained in Guiana, which takes a high polish. --McElrath. To catch a crab (Naut.), a phrase used of a rower:

         1. when he fails to raise his oar clear of the water;

         2. when he misses the water altogether in making a stroke.

crustacean, Old English crabba, from a general Germanic root (compare Dutch krab, Old High German krebiz, German Krabbe, Old Norse krabbi "crab"), related to Low German krabben, Dutch krabelen "to scratch, claw," from PIE root *gerbh- "to scratch, carve" (see carve). The constellation name is attested in English from c.1000; the Crab Nebula (1840), however, is in Taurus, the result of the supernova of 1054, and is so called for its shape. French crabe (13c.) is from Germanic, probably Old Norse.

"fruit of the wild apple tree," c.1300, crabbe, perhaps from Scandinavian (compare Swedish krabbäpple), of obscure origin. The combination of "bad-tempered, combative" and "sour" in the two nouns crab naturally yielded a verb meaning of "to vex, irritate" (c.1400), later "to complain irritably, find fault" (c.1500). The noun meaning "sour person" is from 1570s.

Etymology 1 n. A crustacean of the infraorder Brachyura, having five pairs of legs, the foremost of which are in the form of claws, and a carapace. vb. 1 (context intransitive English) To fish for crabs. 2 (context transitive US slang English) To ruin. 3 (context intransitive English) To complain. 4 (context intransitive nautical aviation English) To drift sideways or to leeward (qualifier: by analogy with the movement of a crab). 5 (context transitive English) To navigate (an aircraft, e.g. a glider) sideways against an air current in order to maintain a straight-line course. 6 (context obsolete World War I English), to fly slightly off the straight-line course towards an enemy aircraft, as the machine guns on early aircraft did not allow firing through the propeller disk. 7 (context rare English) To back out of something. Etymology 2

n. 1 The crab apple or wild apple. 2 The tree bearing crab apples, which has a dogbane-like bitter bark with medical use. 3 A cudgel made of the wood of the crab tree; a crabstick. 4 A movable winch or windlass with powerful gearing, used with derricks, etc. 5 A form of windlass, or geared capstan, for hauling ships into dock, etc. 6 A machine used in ropewalks to stretch the yarn. 7 A claw for anchoring a portable machine. vb. 1 (obsolete) To irritate, make surly or sour 2 To be ill-tempered; to complain or find fault. 3 (British dialect) To cudgel or beat, as with a crabstick Etymology 3

n. The tree species (taxlink Carapa guianensis species noshow=1), native of South Americ

1. Etymology 4

   n. Short for carabiner.

1. v. direct (an aircraft) into a crosswind

2. scurry sideways like a crab

3. fish for crab

4. complain; "What was he hollering about?" [syn: gripe, grouse, beef, squawk, bellyache, holler]

5. [also: crabbing, crabbed]

1. n. decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers

2. a quarrelsome grouch [syn: crabby person]

3. (astrology) a person who is born while the sun is in Cancer [syn: Cancer]

4. the fourth sign of the zodiac; the sun is in this sign from about June 21 to July 22 [syn: Cancer, Cancer the Crab]

5. the edible flesh of any of various crabs [syn: crabmeat]

6. infests the pubic region of the human body [syn: crab louse, pubic louse, Phthirius pubis]

7. a stroke of the oar that either misses the water or digs too deeply; "he caught a crab and lost the race"

8. [also: crabbing, crabbed]

Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting " tail" ( abdomen) ( = short, = tail), usually entirely hidden under the thorax. They live in all the world's oceans, in fresh water, and on land, are generally covered with a thick exoskeleton and have a single pair of claws. Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs, and crab lice – are not true crabs.

A crab is a water-dwelling creature, a decapod crustacean of the infraorder Brachyura. A related common meaning is crab meat.

Crab may also refer to:

The Crab is the name given to a body position sometimes seen in basic gymnastics, yoga, and breakdancing. The body is supinated so that the back turns to the ground, the legs are bent like sitting in a chair, and the arms extend straight backward. Only the feet and hands touch the ground, and the torso is held parallel with the ground. The position's name originates from that of a crab.

The position is said to strengthen the arms, legs and back.

In cryptography, Crab is a block cipher proposed by Burt Kaliski and Matt Robshaw at the first Fast Software Encryption workshop in 1993. Not really intended for use, Crab was developed to demonstrate how ideas from hash functions could be used to create a fast cipher.

Crab has an unusually large block size of 8192 bits. Its creators suggested using an 80-bit key, but the cipher could use any key size. The authors didn't specify an actual key schedule, only that the key is used to generate two large sets of subkeys: a permutation of the numbers 0 through 255, and an array of 2048 32-bit numbers. The block is divided into 256 32-bit subblocks, which are permuted at the beginning. Then the algorithm makes four passes over the data, each time applying one of four transformations adapted from MD5.

A brief note on the cryptanalysis of Crab is included in Markku-Juhani Saarinen's paper on block ciphers based on SHA-1 and MD5, published at FSE 2003. The author demonstrates a weakness in Crab that permits a distinguisher using no more than a dozen chosen plaintexts, and speculates that this can be converted into a full key-recovery attack using no more than 2 chosen plaintexts. Such an attack would depend on the key schedule used.

A crab is a type of scratch used by turntablists. It is made from a combination of moving the record on the turntable by hand and quick movement of the crossfader.

A Crab is a standard astrophotometrical unit for measurement of the intensity of Astrophysical X-ray sources. One Crab is defined as the intensity of the Crab Nebula at the corresponding X-ray photon energy.

The Crab Nebula, and the Crab Pulsar within it, is an intense space X-ray source. It is used as a standard candle in the calibration procedure of X-ray instruments in space. However, because of the Crab Nebula's variable intensity at different X-ray energies, conversion of the Crab to another units depends on the X-ray energy range of interest.

In the photon energy range from 2 to 10 keV, 1 Crab equals 2.4 · 10 erg cm s = 15 keV cm s = 2.4 · 10 W m. For energies greater than ~30 keV, the Crab Nebula becomes unsuitable for calibration purposes, as its flux can no longer be characterized by a single coherent model.

The unit mCrab, or milliCrab, is sometimes used instead of the Crab.

Crab also known as Old Crab and Mr. Panton's Crab (1722 – December 1750) was a British Thoroughbred racehorse. After retiring from racing he became a successful stallion and was British Champion sire in 1748, 1749 and 1750. He was owned by the 1st Earl of Portmore until purchased by Mr. Cotton and then Thomas Panton.