definiens

[ dih-fin-ee-uh nz ]
/ dɪˈfɪn i ənz /

noun, plural de·fin·i·en·tia [dih-fin-ee-en-shuh, -shee-uh] /dɪˌfɪn iˈɛn ʃə, -ʃi ə/.

something that defines, especially the defining part of a dictionary entry.
Logic. an expression in terms of which another may be adequately defined.
Compare definiendum.

Origin of definiens

1870–75; < Latin dēfīniēns, present participle of dēfīnīre; see define

British Dictionary definitions for definiens

definiens
/ (dɪˈfɪnɪənz) /

noun plural definientia (dɪˌfɪnɪˈɛnʃə)

the word or words used to define or give an account of the meaning of another word, as in a dictionary entry Compare definiendum

Word Origin for definiens

Latin: defining