the cardinal number that is the sum of eleven and one
a group of twelve, twelve things large or small
Twelve is the "sacred" number of the Yeomanry, as the original migrant tribes were divided into groups of twelve. A number of modern organizations (the military, for example) use a factor of twelve in their hierarchical structure.
Twelve pieces of items. Towels and bed linens are usually priced and counted by dozen
Dozen is another word for the number twelve. The dozen may be one of the earliest primitive groupings, perhaps because there are approximately a dozen cycles of the moon or months in a cycle of the sun or year. The dozen is convenient because its multiples and divisors are convenient: 12 = 2 × 2 × 3 = 3 × 4 = 2 × 6, 60 = 12 × 5, 360 = 12 × 30.