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.