Pronunciation: (di-fin"ē-en'dum), [key]
—pl. -daPronunciation: (-du). [key]
1. something that is or is to be defined, esp. the term at the head of a dictionary entry.
2. Logic.an expression to be defined in terms of another expression previously defined. Cf. definiens.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.