bow tie vs bowtie

bow tie and bowtie both are nouns.

Word	Noun	Adjective	Verb	Adverb
bow tie	Yes	No	No	No
bowtie	Yes	No	No	No

As nouns, bow tie and bowtie are synonyms defined as:

Other synonyms of bow tie include bow-tie.

bow tie (noun)	bowtie (noun)
a man's tie that ties in a bow	a man's tie that ties in a bow