nightdress vs nightgown

nightdress and nightgown both are nouns.

Word	Noun	Adjective	Verb	Adverb
nightdress	Yes	No	No	No
nightgown	Yes	No	No	No

As nouns, nightdress and nightgown are synonyms defined as:

nightdress and nightgown: lingerie consisting of a loose dress designed to be worn in bed by women

Other synonyms of nightdress include gown, night-robe, nightie.

nightdress (noun)	nightgown (noun)
lingerie consisting of a loose dress designed to be worn in bed by women	lingerie consisting of a loose dress designed to be worn in bed by women