How do you say French face?
Visage is the French word for "face".
"Fermez la bouche!" (pronounced FER-meh lah BOOSH) is the popular way of saying "Shut up." Literally it means, "Shut the mouth." You don't say "your" when describing one's body parts. For "shut your face" you would say "Fermez le visage!" (pronounced FER-meh luh vee-SAHZH) but it may be mistranslated by a french speaker as idiocy. Also, "ta gueule !"