direct antonym vs opposite word

direct antonym and opposite word both are nouns.

Word	Noun	Adjective	Verb	Adverb
direct antonym	Yes	No	No	No
opposite word	Yes	No	No	No

As nouns, opposite word is a hypernym of direct antonym; that is, opposite word is a word with a broader meaning than direct antonym:

direct antonym: antonyms that are commonly associated (e.g., `wet' and `dry')
opposite word: a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other

Other hypernyms of direct antonym include antonym, opposite.

direct antonym (noun)	opposite word (noun)
antonyms that are commonly associated (e.g., `wet' and `dry')	a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other