blessing vs benison

blessing and benison both are nouns.

Word	Noun	Adjective	Verb	Adverb
blessing	Yes	No	No	No
benison	Yes	No	No	No

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

blessing (noun)	benison (noun)
the act of praying for divine protection	a spoken blessing
the formal act of approving
a ceremonial prayer invoking divine protection
a short prayer of thanks before a meal
a desirable state