winder vs watch key

winder and watch key both are nouns.

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

As nouns, watch key is a hyponym of winder; that is, watch key is a word with a more specific, narrower meaning than winder:

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

winder (noun)	watch key (noun)
mechanical device around which something can be wound	winder consisting of a key with a square hole; used for winding some watches
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)