Characteristic

Char`ac*ter*is"tic (?), a. [Gr. ?: cf. F. charactéristique.] Pertaining to, or serving to constitute, the character; showing the character, or distinctive qualities or traits, of a person or thing; peculiar; distinctive.

Characteristic clearness of temper.
Macaulay.

Char`ac*ter*is"tic, n. 1. A distinguishing trait, quality, or property; an element of character; that which characterized. Pope.

The characteristics of a true critic.
Johnson.

2. (Math.) The integral part (whether positive or negative) of a logarithm.