weight (redirected from weights)

weight (wat)

1. heaviness; the degree to which a body is drawn toward the earth by gravity. Abbreviated wt.

2. in statistics, the process of assigning greater importance to some observations than to others, or a mathematical factor used to apply such a process.

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apothecaries' weight  a system of weights used in compounding prescriptions, based on the grain (64.8 mg). Its units are the scruple (20 grains), dram (3 scruples), ounce (8 drams), and pound (12 ounces).

atomic weight  the sum of the masses of the constituents of an atom; it can be expressed in atomic mass units, SI units, or as a dimensionless ratio based on its value relative to the 12C isotope of carbon, defined as 12.00000. Abbreviated At wt.

avoirdupois weight  the system of weight commonly used for ordinary commodities in English-speaking countries; its units are the grain, dram (27.344 grains), ounce (16 drams), and pound (16 ounces).

equivalent weight  the amount of a substance that combines with or displaces 8.0 g of oxygen (or 1.008 g of hydrogen); it is the ratio of the molecular weight to the number of protons (acid/base reactions) or electrons (redox reactions) involved in the reaction.

molecular weight  the weight of a molecule of a substance as compared with that of an atom of carbon-12; it is equal to the sum of the atomic weights of its constituent atoms and is dimensionless. Abbreviated Mol wt or MW. Although widely used, it is not technically correct; relative molecular mass (M r) is preferable.

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weight (wt)

n. Abbr. wt

1. The force with which a body is attracted to Earth or another celestial body and which is equal to the product of the object's mass and the acceleration of gravity.

2. A measure of the heaviness of an object.

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weight,

n the product of the gravitational acceleration of one body and the mass of an attracted body; the measurement in pounds and ounces of how heavy an object is. In the metric system, weight (force) is measured in kg × m/sec².

weight, molecular

n the sum of the atomic weights of all atoms in a molecule.

weight, rubber dam,

n a piece of metal varying in shape and weight, attached to a clip that is hung on the bottom of a placed rubber dam to keep the field of operation clear.

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weight

heaviness; the degree to which a body is drawn toward the earth by gravity. See also Tables 4.1 and 4.2.

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apothecaries' weight

an outmoded system of weight used in compounding prescriptions based on the grain (equivalent 64.8 mg). Its units are the scruple (20 grains), dram (3 scruples), ounce (8 drams) and pound (12 ounces). See also Tables 4.2 and 4.3.

atomic weight

the weight of an atom of a chemical element, compared with the weight of an atom of carbon-12, which is taken as 12.00000.

avoirdupois weight

the system of weight still used for ordinary commodities in some English-speaking countries. Its units are the dram (27.344 grains), ounce (16 drams) and pound (16 ounces).

birth weight

weight of the newborn at the time of birth.

body weight

the animal's weight. In herbivores this is often debatable because of the variation in 'gut-fill' depending on the availability of palatable food. In the absence of scales the weights of large animals are often estimated on the basis of their age and their girth just behind the elbow. Called also liveweight. See also body condition score.

body weight-to-surface area

determination of many drug dosages is physiologically more accurate when based on body surface area rather than body weight; used particularly in cancer chemotherapy. For conversion table for use in dogs see Table 21.

equivalent weight

the weight in grams of a substance that is equivalent in a chemical reaction to 1.008 g of hydrogen. See also chemical equivalent.

weight gain

increase in body weight for specific periods; the principal measure of productivity in meat animals.

weight loss

the loss of body weight from that previously measured. This estimate must take into account the difference in 'gut-fill' and the effects of developing pregnancy and recent parturition.

metric weight

see Tables 4.1 and 4.2.

molecular weight

the weight of a molecule of a chemical compound as compared with the weight of an atom of carbon-12; it is equal to the sum of the weights of its constituent atoms. Abbreviated mol. wt. See also Table 6.

shifting weight limb to limb

sign indicative of lameness especially in horses; while standing the horse is continually shifting its weight from one limb to the opposite one of the pair.