jammies vs sleepwear

jammies and sleepwear both are nouns.

Word	Noun	Adjective	Verb	Adverb
jammies	Yes	No	No	No
sleepwear	Yes	No	No	No

As nouns, sleepwear is a hypernym of jammies; that is, sleepwear is a word with a broader meaning than jammies:

jammies: (usually plural) loose-fitting nightclothes worn for sleeping or lounging; have a jacket top and trousers
sleepwear: garments designed to be worn in bed

Other hypernyms of jammies include nightclothes, nightwear.

jammies (noun)	sleepwear (noun)
(usually plural) loose-fitting nightclothes worn for sleeping or lounging; have a jacket top and trousers	garments designed to be worn in bed