pertaining to a function whose domain is a given set and whose range is contained in that set.
Origin
1570-80; < Latinūn(us) one + -ary, on the model of binary
British Dictionary definitions for unary
unary
/ˈjuːnərɪ/
adjective
1.
consisting of, or affecting, a single element or component; monadic
Word Origin
C16 (in the obsolete sense: a unit): from Latin unus one + -ary
Word Origin and History for unary
adj.
1923, from Latin unus "one" (see one) on model of binary, etc.
unary in Technology
1. (or "monadic") A description of a function or operator which takes one argument, e.g. the unary minus operator which negates its argument. The term is part of the same sequence as nullary and binary. 2. Base one. A number base with only one digit, namely zero, and which can therefore only be used to express the number zero. Attempting to add one to zero results in an infinite sequence of carries. Numbers in unary notation can be represented particularly efficiently however since each digit requires no storage. (2001-02-25)