Characteristic

[Fr. caractéristique, Gr. χαρακτηριστικός.] Serving to constitute the character; serving to mark the peculiar distinctive qualities of a person or thing; peculiar; appropriate. “Characteristic clearness of temper.” Macaulay.

n. 1. That which constitutes a character; that which characterizes; that which distinguishes a person or thing from another. “The characteristics of a true critic.” Johnson. 2. (Math.) The index or exponent of a logarithm.