Like an ape or monkey, in any sense; apish; rhesian; simious: as, simian characters, habits, traits, tricks, antics, etc.Technically, of or pertaining to the Simiidæ or Simiinæ; anthropoid or manlike, as one of the higher apes: as, simian ancestors.n. An ape or monkey of any kind.n. An anthropoid ape of the family Simiidæ.