Possible Clues:

• 'He is a tall, skinny guy with a long, sad, mean-looking --, and a mournful voice' (Damon Runyon, Furthermore)
• Puss
• Skiers may provide one with an oral greeting
• Casanova's mouth
• Mouth, as it were
• Skiers (anag.)
• Mouth, so to speak
• The mouth part of 19 down
• Slangy face of osculatory origin
• That's slang, by mouth