waistband vs sash

waistband and sash both are nouns.

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

As nouns, waistband and sash are synonyms defined as:

waistband and sash: a band of material around the waist that strengthens a skirt or trousers

Other synonyms of waistband include cincture, girdle, waistcloth.

waistband (noun)	sash (noun)
a band of material around the waist that strengthens a skirt or trousers	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