nightcap

Nightcap means: A warm cloth cap worn while sleeping, often with pajamas, being common attire in northern Europe before effective home heating became widespread.. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.

nightcap means: A warm cloth cap worn while sleeping, often with pajamas, being common attire in northern Europe before effective home heating became widespread.. Register: neutral, standard English. A common learner mistake is using the word in a register it does not fit, or assuming a single global meaning; native speakers immediately notice when slang appears in formal contexts, so always check the surrounding register before producing it yourself.