What is "poise"

Poise \Poise\, v. i. To hang in equilibrium; to be balanced or suspended; hence, to be in suspense or doubt.

The slender, graceful spars Poise aloft in air.
--Longfellow.

Poise \Poise\, v. t. [imp. & p. p. Poised, ; p. pr. & vb. n. Poising.] [OE. poisen, peisen, OF. & F. peser, to weigh, balance, OF. il peise, il poise, he weighs, F. il p[`e]se, fr. L. pensare, v. intens. fr. pendere to weigh. See Poise, n., and cf. Pensive.] [Formerly written also peise.]

1. To balance; to make of equal weight; as, to poise the scales of a balance.

2. To hold or place in equilibrium or equiponderance.

   Nor yet was earth suspended in the sky; Nor poised, did on her own foundation lie.
   --Dryden.

3. To counterpoise; to counterbalance.

   One scale of reason to poise another of sensuality.
   --Shak.

   To poise with solid sense a sprightly wit.
   --Dryden.

4. To ascertain, as by the balance; to weigh.

   He can not sincerely consider the strength, poise the weight, and discern the evidence.
   --South.

5. To weigh (down); to oppress. [Obs.]

   Lest leaden slumber peise me down to-morrow.
   --Shak.

Poise \Poise\, n. [OE. pois, peis, OF. pois, peis, F. poids, fr. L. pensum a portion weighed out, pendere to weigh, weigh out. Cf. Avoirdupois, Pendant, Poise, v.] [Formerly written also peise.]

1. Weight; gravity; that which causes a body to descend; heaviness. ``Weights of an extraordinary poise.''
   --Evelyn.

2. The weight, or mass of metal, used in weighing, to balance the substance weighed.

3. The state of being balanced by equal weight or power; equipoise; balance; equilibrium; rest.
   --Bentley.

4. That which causes a balance; a counterweight.

   Men of unbounded imagination often want the poise of judgment.
   --Dryden.

5. a dignified and self-confident manner; graceful composure and tact in handling difficult social situations.

early 15c., "weight, quality of being heavy," later "significance, importance" (mid-15c.), from Old French pois "weight, balance, consideration" (12c., Modern French poids), from Medieval Latin pesum "weight," from Latin pensum "something weighted or weighed," (source of Provençal and Catalan pes, Spanish, Portuguese, Italian peso), noun use of neuter past participle of pendere "to weigh" (see pendant).\n

\nThe sense of "steadiness, composure" first recorded 1640s, from notion of being equally weighted on either side (1550s). Meaning "balance" is from 1711; meaning "way in which the body is carried" is from 1770.

late 14c., "to have a certain weight," from stressed form of Old French peser "to weigh, be heavy; weigh down, be a burden; worry, be a concern," from Vulgar Latin *pesare, from Latin pensare "to weigh carefully, weigh out, counter-balance," frequentative of pendere (past participle pensus) "to weigh" (see pendant). For form evolution from Latin to French, see OED. Meaning "to place in equilibrium" is from 1630s (compare equipoise). Passive sense of "to be ready" (to do something) is from 1932. Related: Poised; poising. In 15c. a poiser was an official who weighed goods.

n. 1 (context obsolete English) weight; an amount of weight, the amount something weighs. 2 The weight, or mass of metal, used in weighing, to balance the substance weighed. 3 That which causes a balance; a counterweight. 4 A state of balance, equilibrium or stability 5 composure; freedom from embarrassment or affectation 6 mien; bearing or deportment of the head or body 7 A condition of hovering, or being suspended 8 (context physics English) A cgs unit of dynamic viscosity equal to one dyne-second per square centimeter. vb. 1 (context obsolete English) To hang in equilibrium; to be balanced or suspended; hence, to be in suspense or doubt. 2 (context obsolete English) To counterpoise; to counterbalance. 3 (context obsolete English) To be of a given weight; to weigh. (14th-17th c.) 4 (context obsolete English) To add weight to, to weigh down. (16th-18th c.) 5 (context now rare English) To hold (something) (term with English) or (term against English) something else in equilibrium; to balance, counterpose. (from 16th c.) 6 To hold (something) in equilibrium, to hold balanced and ready; to carry (something) ready to be used. (from 16th c.) 7 To keep (something) in equilibrium; to hold suspended or balanced. (from 17th c.) 8 To ascertain, as if by balancing; to weigh.

1. n. a cgs unit of dynamic viscosity equal to one dyne-second per square centimeter; the viscosity of a fluid in which a force of one dyne per square centimeter maintains a velocity of 1 centimeter per second

2. a state of being balanced in a stable equilibrium

3. great coolness and composure under strain; "keep your cool" [syn: aplomb, assuredness, cool, sang-froid]

4. v. be motionless, in suspension; "The bird poised for a few moments before it attacked"

5. prepare (oneself) for something unpleasant or difficult [syn: brace]

6. cause to be balanced or suspended

7. hold or carry in equilibrium [syn: balance]

The poise (symbol P, ) is the unit of dynamic viscosity in the centimetre gram second system of units. It is named after Jean Léonard Marie Poiseuille.

1 P = 0.100 kg ⋅ m ⋅ s = 1 g ⋅ cm ⋅ s

The analogous unit in the International System of Units is the pascal second (Pa·s):

1 Pa ⋅ s = 1 kg ⋅ m ⋅ s = 10 P

The poise is often used with the metric prefix centi- because the viscosity of water at 20°C is almost exactly 1 centipoise. A centipoise is one one-hundredth of a poise, and one millipascal-second (mPa·s) in SI units. (1 cP = 10 Pa·s = 1 mPa·s)

The centipoise is properly abbreviated cP, but the alternative abbreviations cps, cp, and cPs are also commonly seen.

Water has a viscosity of 0.00899 poise at 25 °C and a pressure of 1 atmosphere. (0.00899 P = 0.899cP = 0.899 mPa·s)