bow window vs bay window

bow window and bay window both are nouns.

Word	Noun	Adjective	Verb	Adverb
bow window	Yes	No	No	No
bay window	Yes	No	No	No

As nouns, bow window and bay window are synonyms defined as:

bow window and bay window: a window that sticks out from the outside wall of a house

bow window (noun)	bay window (noun)
a window that sticks out from the outside wall of a house	a window that sticks out from the outside wall of a house
	slang for a paunch