supplication vs petition

supplication and petition both are nouns.

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

As nouns, petition is a hypernym of supplication; that is, petition is a word with a broader meaning than supplication:

Other hypernyms of supplication include orison, prayer.

supplication (noun)	petition (noun)
the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)	a formal message requesting something that is submitted to an authority
a prayer asking God's help as part of a religious service	reverent petition to a deity
a humble request for help from someone in authority

supplication (verb)	petition (verb)
	write a petition for something to somebody; request formally and in writing