chunky heel vs nan heel

chunky heel and nan heel both are nouns.

Word	Noun	Adjective	Verb	Adverb
chunky heel	Yes	No	No	No
nan heel	Yes	No	No	No

As nouns, nan heel is a hyponym of chunky heel; that is, nan heel is a word with a more specific, narrower meaning than chunky heel:

chunky heel: A type of wide heel that is usually square; comes in various heights.
nan heel: A type of short chunky heel.

chunky heel (noun)	nan heel (noun)
A type of wide heel that is usually square; comes in various heights.	A type of short chunky heel.