Definitions for "Vocative"
Of or pertaining to calling; used in calling; specifically (Gram.), used in address; appellative; -- said of that case or form of the noun, pronoun, or adjective, in which a person or thing is addressed; as, Domine, O Lord.
The vocative case.
the case used to indicate direct address You're a good man, Charlie Brown.
an optional nominal in interactive discourse which clearly signals to the person or persons concerned, that the clause refers to him/her/them
a phrase, which represents the person, to whom the statement is referring
a word or phrase intended to directly address or get a person's attention