eye-drop vs irrigation

eye-drop and irrigation both are nouns.

Word	Noun	Adjective	Verb	Adverb
eye-drop	Yes	No	No	No
irrigation	Yes	No	No	No

As nouns, irrigation is a hypernym of eye-drop; that is, irrigation is a word with a broader meaning than eye-drop:

eye-drop: a method of irrigating the eye used by ophthalmologists
irrigation: (medicine) cleaning a wound or body organ by flushing or washing out with water or a medicated solution

eye-drop (noun)	irrigation (noun)
a method of irrigating the eye used by ophthalmologists	supplying dry land with water by means of ditches etc
a drop from an eye dropper	(medicine) cleaning a wound or body organ by flushing or washing out with water or a medicated solution