What is singular? What is singular? Grammar Of, relating to, or being a noun, pronoun, or adjective denoting a single person or thing or several entities considered as a single unit.Being only one; individual.Being the only one of a kind; unique. Being beyond what is ordinary or usual; remarkable.Deviating from the usual or expected; odd. See Synonyms at strange.Grammar Of, relating to, or being a verb expressing the action or state of a single subject.Logic Of or relating to the specific as distinguished from the general; individual.Grammar The singular number or a form designating it.Grammar A word having a singular number.