Adjective
(mathematics, of a function) Taking no entries; having trivial domain; having the arity of zero.
(programming, of a function, procedure, command, etc.) Taking no arguments.
Source: en.wiktionary.orgPolyadic or multiary means n-ary for some nonnegative integer n. A 0-ary, or nullary, quasigroup is just a constant element of Q. A 1-ary, or unary, quasigroup is a bijection of Q to itself. Source: Internet
Nullary Sometimes it is useful to consider a constant to be an operation of arity 0, and hence call it nullary. Source: Internet
One combines a Latin prefix with the -ary ending; for example: * A nullary function takes no arguments. Source: Internet
In the nullary case, one can derive truth from no premises. Source: Internet