nightdress vs nightie

nightdress and nightie both are nouns.

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

As nouns, nightdress and nightie are synonyms defined as:

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

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

nightdress (noun)	nightie (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