OPERABLE
Op"er*a*ble, a.

Defn: Practicable. [Obs.]

OPERAMETER
Op`er*am"e*ter, n. Etym: [L. opus, operis, pl. opera work + -meter.]

Defn: An instrument or machine for measuring work done, especially for ascertaining the number of rotations made by a machine or wheel in manufacturing cloth; a counter. Ure.

OPERANCE; OPERANCY
Op"er*ance, Op"er*an*cy, n.

Defn: The act of operating or working; operation. [R.]

OPERAND Op"er*and, n. Etym: [From neuter of L. operandus, gerundive of operari. See Operate.] (Math.)

Defn: The symbol, quantity, or thing upon which a mathematical operation is performed; — called also faciend.

OPERANT
Op"er*ant, a. Etym: [L. operans, p.pr. of operari. See Operate.]

Defn: Operative. [R.] Shak.
— n.