(slang) making a strange face

appearance of the face

(literally) to put out or show one's face / (figuratively) to appear; to become visible

widely known, well-known, well connected

(slang) o-face, a facial expression during orgasm

(archaic) red-faced / (archaic) embarrassed, guilty of conscience

an emoticon

(medicine) attached to the names of conditions

difficult / hard, probably impossible

to recall, to remember / to learn / to memorize / to feel (an emotion or sense)