Pj's and Sleepwear

Pj's noun - (usually plural) loose-fitting nightclothes worn for sleeping or lounging; have a jacket top and trousers.

Sleepwear and pj's are semantically related. In some cases you can use "Sleepwear" instead a noun "Pj's".

Sleepwear noun - Garments designed to be worn in bed.

Pj's and sleepwear are semantically related. Sometimes you can replace term "Pj's" with "Sleepwear", this nouns are similar.