have a screw loose

"have a screw loose" means: To be insane, irrational, or eccentric.. 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.

"have a screw loose" means: To be insane, irrational, or eccentric.. Register: informal slang, fine in casual conversation, texting and social media but not in academic essays, business writing or formal speech. A common non-native mistake is to use the word in the wrong register, or to assume one fixed meaning when it is actually polysemous; always check the surrounding register and the audience before producing it yourself. In formal writing, prefer a neutral synonym or a short descriptive phrase, and use this word only when you have heard or read it being used naturally in a comparable context.