commode vs lavatory

commode and lavatory both are nouns.

Word	Noun	Adjective	Verb	Adverb
commode	Yes	No	No	No
lavatory	Yes	No	No	No

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

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

commode (noun)	lavatory (noun)
a plumbing fixture for defecation and urination	a room or building equipped with one or more toilets
a tall elegant chest of drawers	a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face
	a toilet that is cleaned of waste by the flow of water through it