part vs heavy

part and heavy both are nouns.

Word	Noun	Adjective	Verb	Adverb
part	Yes	No	Yes	Yes
heavy	Yes	Yes	No	Yes

As nouns, heavy is a hyponym of part; that is, heavy is a word with a more specific, narrower meaning than part:

Other hyponyms of part include bit part, minor role, hero, ingenue, name part, title role, heroine, baddie, villain.

part (noun)	heavy (noun)
the actions and activities assigned to or required or expected of a person or group	a serious (or tragic) role in a play
the effort contributed by a person in bringing about a result	an actor who plays villainous roles
something less than the whole of a human artifact
an item that is an instance of some type
a line of scalp that can be seen when sections of hair are combed in opposite directions
one of the portions into which something is regarded as divided and which together constitute a whole
an actor's portrayal of someone in a play
that which concerns a person with regard to a particular role or situation
the melody carried by a particular voice or instrument in polyphonic music
the extended spatial location of something
a portion of a natural object
assets belonging to or due to or contributed by an individual person or group
something determined in relation to something that includes it

part (adjective)	heavy (adjective)
	of comparatively great physical weight or density
	marked by great psychological weight; weighted down especially with sadness or troubles or weariness
	unusually great in degree or quantity or number
	of the military or industry; using (or being) the heaviest and most powerful armaments or weapons or equipment
	(physics, chemistry) being or containing an isotope with greater than average atomic mass or weight
	of great intensity or power or force
	darkened by clouds
	(used of soil) compact and fine-grained
	(of sleep) deep and complete
	lacking lightness or liveliness
	characterized by effort to the point of exhaustion; especially physical effort
	usually describes a large person who is fat but has a large frame to carry it
	full of; bearing great weight
	full and loud and deep
	large and powerful; especially designed for heavy loads or rough work
	slow and laborious because of weight
	of great gravity or crucial import; requiring serious thought
	dense or inadequately leavened and hence likely to cause distress in the alimentary canal
	given to excessive indulgence of bodily appetites especially for intoxicating liquors
	in an advanced stage of pregnancy
	sharply inclined
	made of fabric having considerable thickness
	(of an actor or role) being or playing the villain
	requiring or showing effort
	permitting little if any light to pass through because of denseness of matter
	prodigious
	of relatively large extent and density

part (verb)	heavy (verb)
move or break apart
force, take, or pull apart
depart for someplace
go one's own way; move apart
discontinue an association or relation; go different ways

part (adverb)	heavy (adverb)
to some extent; in some degree; not wholly	slowly as if burdened by much weight