irrigation vs lavage

irrigation and lavage both are nouns.

Word	Noun	Adjective	Verb	Adverb
irrigation	Yes	No	No	No
lavage	Yes	No	No	No

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

irrigation: (medicine) cleaning a wound or body organ by flushing or washing out with water or a medicated solution
lavage: washing out a hollow organ (especially the stomach) by flushing with water

Other hyponyms of irrigation include eye-drop, eyedrop, douche, clyster, enema.

irrigation (noun)	lavage (noun)
supplying dry land with water by means of ditches etc	washing out a hollow organ (especially the stomach) by flushing with water
(medicine) cleaning a wound or body organ by flushing or washing out with water or a medicated solution