"facehole" means: Facehole is blunt, irreverent slang for the mouth — usually used to tell someone to shut it, to describe eating, or just to be deliberately.... This is informal slang, common in casual speech, texting and social media, but not appropriate for school work, applications or professional settings. There is no real cause for concern in itself; it is everyday peer vocabulary. If your child uses it, a light comment about audience and register is usually enough — no need to escalate. Context, more than the word, tells you whether to follow up.