OPPUGNATION
Op`pug*na"tion, n. Etym: [L. oppugnatio: cf. OF. oppugnation.]

Defn: Opposition. [R.] Bp. Hall.

OPPUGNER
Op*pugn"er, n.

Defn: One who opposes or attacks; that which opposes. Selden.

OPSIMATHY
Op*sim"a*thy, n. Etym: [Gr.

Defn: Education late in life. [R.] Hales.

OPSIOMETER
Op`si*om"e*ter, n. Etym: [Gr. -meter: cf. F. opsiomètre.]

Defn: An instrument for measuring the limits of distincts vision in different individuals, and thus determiming the proper focal length of a lens for correcting imperfect sight. Brande & C.

OPSONATION
Op`so*na"tion, n. Etym: [L. opsonatio.]

Defn: A catering; a buying of provisions. [Obs.] Bailey.