expire vs drown

expire and drown both are verbs.

Word	Noun	Adjective	Verb	Adverb
expire	No	No	Yes	No
drown	No	No	Yes	No

As verbs, drown is a hyponym of expire; that is, drown is a word with a more specific, narrower meaning than expire:

expire: pass from physical life and lose all bodily attributes and functions necessary to sustain life
drown: die from being submerged in water, getting water into the lungs, and asphyxiating

Other hyponyms of expire include abort, asphyxiate, stifle, suffocate, buy it, pip out, predecease, famish, starve, fall, succumb, yield.

expire (verb)	drown (verb)
expel air	die from being submerged in water, getting water into the lungs, and asphyxiating
pass from physical life and lose all bodily attributes and functions necessary to sustain life	kill by submerging in water
lose validity	get rid of as if by submerging
	cover completely or make imperceptible
	be in danger of dying from submersion in a liquid and asphyxiation
	be covered with or submerged in a liquid