What is "sear"

Sear \Sear\, Sere \Sere\ (s[=e]r), a. [OE. seer, AS. se['a]r (assumed) fr. se['a]rian to wither; akin to D. zoor dry, LG. soor, OHG. sor[=e]n to wither, Gr. a"y`ein to parch, to dry, Skr. [,c]ush (for sush) to dry, to wither, Zend hush to dry. Dry; withered; no longer green; -- applied to leaves.
--Milton.

I have lived long enough; my way of life Is fall'n into the sear, the yellow leaf.
--Shak.

Sear \Sear\, n. [F. serre a grasp, pressing, fr. L. sera. See Serry.] The catch in a gunlock by which the hammer is held cocked or half cocked.

Sear spring, the spring which causes the sear to catch in the notches by which the hammer is held.

Sear \Sear\, v. t. [imp. & p. p. Seared; p. pr. & vb. n. Searing.] [OE. seeren, AS. se['a]rian. See Sear, a.]

1. To wither; to dry up.
   --Shak.

2. To burn (the surface of) to dryness and hardness; to cauterize; to expose to a degree of heat such as changes the color or the hardness and texture of the surface; to scorch; to make callous; as, to sear the skin or flesh. Also used figuratively.

   I'm seared with burning steel.
   --Rowe.

   It was in vain that the amiable divine tried to give salutary pain to that seared conscience.
   --Macaulay.

   The discipline of war, being a discipline in destruction of life, is a discipline in callousness. Whatever sympathies exist are seared.
   --H. Spencer.

   Note: Sear is allied to scorch in signification; but it is applied primarily to animal flesh, and has special reference to the effect of heat in marking the surface hard. Scorch is applied to flesh, cloth, or any other substance, and has no reference to the effect of hardness.

   To sear up, to close by searing. ``Cherish veins of good humor, and sear up those of ill.''
   --Sir W. Temple.

Old English searian (intransitive) "dry up, to wither," from Proto-Germanic *saurajan (cognates: Middle Dutch soor "dry," Old High German soren "become dry"), from root of sear "dried up, withered" (see sere). Meaning "cause to wither" is from early 15c. Meaning "to brand, to burn by hot iron" is recorded from c.1400, originally especially of cauterizing wounds; figurative use is from 1580s. Related: Seared; searing.

Etymology 1

1. dry; withered, especially of vegetation. Etymology 2

   n. 1 A scar produced by searing 2 Part of a gun that retards the hammer until the trigger is pulled. v

2. 1 To char, scorch, or burn the surface of something with a hot instrument. 2 To wither; to dry up. 3 (context figurative English) To mark permanently, as if by burning.

adj. (used especially of vegetation) having lost all moisture; "dried-up grass"; "the desert was edged with sere vegetation"; "shriveled leaves on the unwatered seedlings"; "withered vines" [syn: dried-up, sere, shriveled, shrivelled, withered]

1. v. make very hot and dry; "The heat scorched the countryside" [syn: scorch]

2. become superficially burned; "my eyebrows singed when I bent over the flames" [syn: scorch, singe]

3. cause to wither or parch from exposure to heat; "The sun parched the earth" [syn: parch]

Sear may refer to:

• Sear (firearm), part of the trigger mechanism on a firearm
• Seir (demon), a Prince of Hell; also spelled Sear
• Searing, a cooking technique which quickly cooks the exterior of a food item
• Surfactant Enhanced Aquifer Remediation, typically performed with Hydrocarbon Mitigating Surfactants in soil remediation
• Sear, a client for the WorldForge MMORPG framework
• sear.ch, a Swiss search engine
• SAr, electrophilic aromatic substitution, a common reaction in organic chemistry
• SEAR, Siemens Engineering und Anlagenerrichtung Rostock GmbH
• SEAR (mathematics), Sets, Elements, And Relations, a structural set theory in mathematical logic.1
• Sahar Elevated Access Road, a dedicated airport corridor in Mumbai, India.

In a firearm, the sear is the part of the trigger mechanism that holds the hammer, striker, or bolt back until the correct amount of pressure has been applied to the trigger; at which point the hammer, striker, or bolt is released to discharge the weapon. The sear may be a separate part or can be a surface incorporated into the trigger.

As one firearms manufacturer notes:

Sear - A sharp bar, resting in a notch (or in British: "bent") in a hammer (or in British: "tumbler"), holding the hammer back under the tension of the mainspring. When the trigger is pulled, the sear moves out of its notch, releasing the hammer and firing the gun.

The term "sear" is sometimes incorrectly used to describe a complete trigger group.

Within a trigger group, any number of sears may exist. For example, a Ruger Blackhawk single-action revolver contains one for releasing the hammer. A Ruger Redhawk double/single-action revolver contains two, one for single-action release and the other for double-action release. A Browning BLR rifle contains three sears, all used simultaneously for hammer release. On many select-fire rifles two sears exist, one for semi-automatic fire and the second for full-automatic fire. In this case, the selector switch disengages one over the other.

Trigger sears are a key component for trigger pull characteristics. Larger sears create creep while shorter ones produce a crisp pull. Aftermarket trigger companies, such as Bold, Timney, and Jewell, produce products in which sear contact is adjustable for personal preference. When a gunsmith does a "trigger job" to improve the quality and release of a trigger pull, most often the work includes modifying the sear, such as polishing, lapping, etc.

The sear on many firearms is often connected to a disconnector, which, after a cycle of semi-automatic fire has proceeded, keeps the hammer in place until the trigger is released and the sear takes over. Many firearms, such as the M1911 pistol, use a notch in the slide of the handgun that the top end of the disconnector returns to after the trigger is released. When the trigger is still under pressure by the firearm operator, the disconnector will not retract to its resting position. On other handguns, such as the Series 80 version of the M1911, a firing pin block acts as an internal safety, which is disengaged by the disconnector after the trigger is pulled. However, because of the spring tension placed on the disconnector by the firing pin block, the weight of the trigger pull weight is significantly increased.

Trigger pull is related to the interaction of the sear with the trigger and the spring. It can be measured. regulated and adjusted, but it is a complicated mechanical problem.