sunbeam vs irradiation

sunbeam and irradiation both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunbeam	Yes	No	No	No
irradiation	Yes	No	No	No

As nouns, irradiation is a hypernym of sunbeam; that is, irradiation is a word with a broader meaning than sunbeam:

Other hypernyms of sunbeam include beam, beam of light, light beam, ray, ray of light, shaft, shaft of light.

sunbeam (noun)	irradiation (noun)
a ray of sunlight	(medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
	the apparent enlargement of a bright object when viewed against a dark background
	(Pavolvian conditioning) the elicitation of a conditioned response by stimulation similar but not identical to the original stimulus
	(physiology) the spread of sensory neural impulses in the cortex
	a column of light (as from a beacon)
	the condition of being exposed to radiation