The Collaborative International Dictionary of English v.0.48:

hooter \hoot"er\ n.
   1. the nose. [slang]

   Syn: beak, honker, nozzle, snoot, snout, schnozzle.
        [WordNet 1.5]

   2. An automobile horn. [Brit. slang]
      [PJC]

   3. A woman's breast, especially one that is large. [vulgar
      slang]
      [PJC]

WordNet (r) 3.0 (2006):

hooter
    n 1: informal terms for the nose [syn: beak, honker,
         hooter, nozzle, snoot, snout, schnozzle,
         schnoz]
    2: a device on an automobile for making a warning noise [syn:
       automobile horn, car horn, motor horn, horn,
       hooter]
    3: nocturnal bird of prey with hawk-like beak and claws and
       large head with front-facing eyes [syn: owl, bird of
       Minerva, bird of night, hooter]