scrap metal vs trash

scrap metal and trash both are nouns.

Word	Noun	Adjective	Verb	Adverb
scrap metal	Yes	No	No	No
trash	Yes	No	Yes	No

As nouns, trash is a hypernym of scrap metal; that is, trash is a word with a broader meaning than scrap metal:

Other hypernyms of scrap metal include rubbish, scrap.

scrap metal (noun)	trash (noun)
discarded metal suitable for reprocessing	an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant
	nonsensical talk or writing
	worthless people
	worthless material that is to be disposed of

scrap metal (verb)	trash (verb)
	express a totally negative opinion of
	dispose of (something useless or old)