commode vs flush toilet

commode and flush toilet both are nouns.

Word	Noun	Adjective	Verb	Adverb
commode	Yes	No	No	No
flush toilet	Yes	No	No	No

As nouns, flush toilet is a hyponym of commode; that is, flush toilet is a word with a more specific, narrower meaning than commode:

commode: a plumbing fixture for defecation and urination
flush toilet: a toilet that is cleaned of waste by the flow of water through it

Other hyponyms of commode include flushless toilet, lavatory, potty chair, potty seat.

commode (noun)	flush toilet (noun)
a plumbing fixture for defecation and urination	a toilet that is cleaned of waste by the flow of water through it
a tall elegant chest of drawers