Webster's Revised Unabridged Dictionary · 1913

Deponent

Deponent , noun

[Latin deponenes, -entis, laying down. See Depone, transitive verb]

1.
(Law) One who deposes or testifies under oath; one who gives evidence; usually, one who testifies in writing.
2.
(Greek & Lat. Grammar) A deponent verb.

Deponent , adjective

[Latin deponens, -entis, laying down (its proper passive meaning), present participle of deponere: compare French déponent. See Depone.]

(Grammar) Having a passive form with an active meaning, as certain Latin and Greek verbs.