empty vs unload

empty is a noun but unload is not a noun.

Word	Noun	Adjective	Verb	Adverb
empty	Yes	Yes	Yes	No
unload	No	No	Yes	No

As verbs, unload is a hyponym of empty; that is, unload is a word with a more specific, narrower meaning than empty:

Other hyponyms of empty include offload, unlade.

empty (noun)	unload (noun)
a container that has been emptied

empty (adjective)	unload (adjective)
holding or containing nothing
emptied of emotion
needing nourishment
devoid of significance or force

empty (verb)	unload (verb)
excrete or discharge from the body	remove the load from (a container or vehicle)
become empty or void of its content	remove (cargo, people, etc.) from and leave
make void or empty of contents
remove the contents of a container
leave behind empty; move out of