dozen

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A set of 12.
2. n. An indefinite, large number: dozens of errands to run.
3. adj. Twelve.

Century Dictionary and Cyclopedia

1. n. A collection of twelve things; twelve units: used with or without of: as, a dozen eggs, or a dozen of eggs; twelve dozen pairs of gloves. Like other numerical terms denoting more than a few, dozen is often used for an indefinitely great number: as, I have a dozen things to attend to at once. Abbreviated doz.
2. n. In old English law, a municipal district consisting originally of twelve families or householders. Compare tithing, riding, hundred.
3. To make up into bundles of twelve, as certain kinds of dressed hides.

Wiktionary

1. n. A set of twelve.
2. n. A large, unspecified number of, comfortably estimated in small multiples of twelve, thus generally implied to be significantly more than ten or twelve, but less than perhaps one or two hundred; many.
3. n. An old English measure of ore containing 12 hundredweight.

GNU Webster's 1913

1. n. A collection of twelve objects; a tale or set of twelve; with or without of before the substantive which follows.
2. n. An indefinite small number.

WordNet 3.0

1. n. the cardinal number that is the sum of eleven and one
2. adj. denoting a quantity consisting of 12 items or units