heavily vs heavy-duty

heavily is not an adjective while heavy-duty is an adjective.

Word	Noun	Adjective	Verb	Adverb
heavily	No	No	No	Yes
heavy-duty	No	Yes	No	No

heavily (adjective)	heavy-duty (adjective)
	designed for heavy work

heavily (adverb)	heavy-duty (adverb)
to a considerable degree
indulging excessively
slowly as if burdened by much weight
in a manner designed for heavy duty
in a heavy-footed manner
with great force
in a labored manner