1. A measure of the heaviness of an object.
2. The force with which a body is attracted to Earth or another celestial body, equal to the product of the object's mass and the acceleration of gravity.
3. 1. A unit measure of gravitational force: a table of weights and measures.
   2. A system of such measures: avoirdupois weight; troy weight.
4. The measured heaviness of a specific object: a two-pound weight.
5. An object used principally to exert a force by virtue of its gravitational attraction to Earth, especially:
   1. A metallic solid used as a standard of comparison in weighing.
   2. An object used to hold something else down.
   3. A counterbalance in a machine.
   4. Sports. A heavy object, such as a dumbbell, lifted for exercise or in athletic competition.
6. Excessive fat; corpulence: exercising in order to lose weight.
7. Statistics. A factor assigned to a number in a computation, as in determining an average, to make the number's effect on the computation reflect its importance.
8. Oppressiveness; pressure: the weight of responsibilities.
9. The greater part; preponderance: The weight of the evidence is against the defendant.
10. 1. Influence, importance, or authority: Her approval carried great weight. See synonyms at importance.
    2. Ponderous quality: the weight of the speaker's words.
11. Sports. A classification according to comparative lightness or heaviness. Often used in combination: a heavyweight boxer.
12. The heaviness or thickness of a fabric in relation to a particular season or use. Often used in combination: a summerweight jacket.

1. To add to, by or as if by attaching a weight; make heavy or heavier.
2. To load down, burden, or oppress.
3. To increase the weight or body of (fabrics) by treating with chemicals.
4. Statistics. To assign weights or a weight to.
5. To cause to have a slant or bias: weighted the rules in favor of homeowners.
6. Sports. To assign to (a horse) the weight it must carry as a handicap in a race.

by weight

1. According to weight rather than volume or other measure.

1. SportsTo weigh within the limits stipulated for an athletic contest. To weigh within the limits stipulated for an athletic contest.

[Middle English wight, from Old English wiht.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.