the class of objects that an expression refers to; "the extension of `satellite of Mars' is the set containing only Demos and Phobos"
the most direct or specific meaning of a word or expression; the class of objects that an expression refers to; "the extension of `satellite of Mars'' is the set containing only Demos and Phobos"
the act of indicating or pointing out by name
the most direct or specific meaning of a word or expression; the class of objects that an expression refers to
