window sash vs sash

window sash and sash both are nouns.

Word	Noun	Adjective	Verb	Adverb
window sash	Yes	No	No	No
sash	Yes	No	No	No

As nouns, window sash and sash are synonyms defined as:

window sash and sash: a framework that holds the panes of a window in the window frame

window sash (noun)	sash (noun)
a framework that holds the panes of a window in the window frame	a framework that holds the panes of a window in the window frame
	a band of material around the waist that strengthens a skirt or trousers