spokesperson(n = noun.person) interpreter, representative, voice - an advocate who represents someone else's policy or purpose; "the meeting was attended by spokespersons for all the major organs of government"
is a kind of advocate, advocator, exponent, proponent
has particulars: ambassador, flack, flack catcher, flak, flak catcher, mouth, mouthpiece, spokesman, spokeswoman, bagman, commercial traveler, commercial traveller, roadman, traveling salesman, travelling salesman

spokesperson, n. (pl. -persons or -people) a spokesman or spokeswoman.