nightclothes
Word family
Synonym discussion
Sense: noun/1
Nightclothes is the broadest umbrella term, covering any garment worn for sleeping. Nightwear is a slightly more formal or commercial synonym, common in retail contexts (e.g. 'nightwear department'). Sleepwear is also used in marketing and labelling and often includes robes as well as sleeping garments. Pyjamas (or 'pajamas' in American English) is the most specific and common word, referring only to a two-piece set of a top and trousers. In everyday conversation, most speakers would say 'I put on my pyjamas' rather than 'I put on my nightclothes', even though the latter is correct.
Common collocations
Etymology
A compound word formed from 'night' (the period of darkness, from Old English 'niht') and 'clothes' (garments worn on the body, from Old English 'clāþas', plural of 'clāþ'). The compound has been used in English since at least the 16th century to refer specifically to garments worn for sleeping.
First known use
1567
1567, in the meaning defined above