work on vs retread

work on is not a noun while retread is a noun.

Word	Noun	Adjective	Verb	Adverb
work on	No	No	Yes	No
retread	Yes	No	Yes	No

As verbs, retread is a hyponym of work on; that is, retread is a word with a more specific, narrower meaning than work on:

Other hyponyms of work on include hot-work, cold work, coldwork, overwork, make over, rework, rack, tool, till.

work on (noun)	retread (noun)
	a used automobile tire that has been remolded to give it new treads

work on (verb)	retread (verb)
shape, form, or improve a material	give new treads to (a tire)
to exert effort in order to do, make, or perform something	use again in altered form