lighten vs irradiate

lighten and irradiate both are verbs.

Word	Noun	Adjective	Verb	Adverb
lighten	No	No	Yes	No
irradiate	No	No	Yes	No

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

Other hyponyms of lighten include illume, illuminate, illumine, light, light up.

lighten (verb)	irradiate (verb)
make more cheerful through the use of color	expose to radiation
become lighter	cast rays of light upon
alleviate or remove (pressure or stress) or make less oppressive	give spiritual insight to; in religion
become more cheerful
reduce the weight on; make lighter
make more cheerful