prayer vs supplication

prayer and supplication both are nouns.

Word	Noun	Adjective	Verb	Adverb
prayer	Yes	No	No	No
supplication	Yes	No	No	No

As nouns, prayer and supplication are synonyms defined as:

prayer and supplication: the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)

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

Other hyponyms of prayer include adjuration, demagoguery, demagogy, plea, solicitation, suit, courting, courtship, suit, wooing.

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

prayer (noun)	supplication (noun)
the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)	the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)
earnest or urgent request	a prayer asking God's help as part of a religious service
a fixed text used in praying	a humble request for help from someone in authority
reverent petition to a deity
someone who prays to God