From The Collaborative International Dictionary of English v.0.48 :
Operand \Op"er*and\, n. [From neuter of L. operandus, gerundive
of operari. See Operate.] (Math.)
The symbol, quantity, or thing upon which a mathematical
operation is performed; -- called also faciend.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
operand
n 1: a quantity upon which a mathematical operation is performed
From The Free On-line Dictionary of Computing (30 December 2018) :
operand
An argument of an operator or of a machine
language instruction.
(1995-08-18)