dump truck vs motortruck

dump truck and motortruck both are nouns.

Word	Noun	Adjective	Verb	Adverb
dump truck	Yes	No	No	No
motortruck	Yes	No	No	No

As nouns, motortruck is a hypernym of dump truck; that is, motortruck is a word with a broader meaning than dump truck:

dump truck: truck whose contents can be emptied without handling; the front end of the platform can be pneumatically raised so that the load is discharged by gravity
motortruck: an automotive vehicle suitable for hauling

Other hypernyms of dump truck include truck.

dump truck (noun)	motortruck (noun)
truck whose contents can be emptied without handling; the front end of the platform can be pneumatically raised so that the load is discharged by gravity	an automotive vehicle suitable for hauling