Meaning of cofunction

co•func•tion

Pronunciation: (kō'fungk"shun), [key]
— n. Trigonom.
  1. the function of the complement of a given angle or arc: cos&thgr; is the cofunction of sin&thgr;.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.