Definition of face-up:
(n) :
(anatomy) The front part of the head of a human or other animal, featuring the eyes, nose, and mouth, and the surrounding area.
(n) :
(informal or slang) One's facial expression.
(n) :
(informal or slang) (in expressions such as make a face) A distorted facial expression; an expression of displeasure, insult, etc.
(n) :
(informal or slang) (informal) The amount expressed on a bill, note, bond, etc., without any interest or discount; face value.
(n) :
(informal or slang) (slang) The mouth.
(n) :
(informal or slang) (slang) Makeup; one's complete facial cosmetic application.