Twelve \Twelve\, n.

1. The number next following eleven; the sum of ten and two, or of twice six; twelve units or objects; a dozen.

2. A symbol representing twelve units, as 12, or xii.

The Twelve (Script.), the twelve apostles. --Matt. xxvi. 20.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Twelve \Twelve\, a. [OE. twelve, twelf, AS. twelf; akin to OFries. twelf, twelef, twilif, OS. twelif, D. twaalf, G. zw["o]lf, OHG. zwelif, Icel. t?lf, Sw. tolf, Dan. tolv, Goth. twalif, from the root of E. two + the same element as in the second part of E. eleven. See Two, and Eleven.]

One more that eleven; two and ten; twice six; a dozen.

Twelve-men's morris. See the Note under Morris.

Twelve Tables. (Rom. Antiq.) See under Table.

Source: Webster's Revised Unabridged Dictionary (1913)