\Mo*nad"ic\, Monadical \Mo*nad"ic*al\, a. Of, pertaining to, or like, a monad, in any of its senses. See {Monad}, n. --Dr. H. More.
1. unary, when describing an operator or function. The term is part of the dyadic, niladic sequence.
2. See monad.
Webster's 1913 Dictionary