defendant vs accused

defendant and accused both are nouns.

Word	Noun	Adjective	Verb	Adverb
defendant	Yes	No	No	No
accused	Yes	No	No	No

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

defendant: a person or institution against whom an action is brought in a court of law; the person being sued or accused
accused: a defendant in a criminal proceeding

Other hyponyms of defendant include co-defendant, codefendant.

defendant (noun)	accused (noun)
a person or institution against whom an action is brought in a court of law; the person being sued or accused	a defendant in a criminal proceeding