watch key vs winder

watch key and winder both are nouns.

Word	Noun	Adjective	Verb	Adverb
watch key	Yes	No	No	No
winder	Yes	No	No	No

As nouns, winder is a hypernym of watch key; that is, winder is a word with a broader meaning than watch key:

watch key: winder consisting of a key with a square hole; used for winding some watches
winder: mechanical device used to wind another device that is driven by a spring (as a clock)

Other hypernyms of watch key include key.

watch key (noun)	winder (noun)
winder consisting of a key with a square hole; used for winding some watches	mechanical device around which something can be wound
	mechanical device used to wind another device that is driven by a spring (as a clock)
	a worker who winds (e.g., a winch or clock or other mechanism)