plea vs supplication

plea and supplication both are nouns.

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

As nouns, plea and supplication are synonyms defined as:

plea and supplication: a humble request for help from someone in authority

plea (noun)	supplication (noun)
an answer indicating why a suit should be dismissed	the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)
a humble request for help from someone in authority	a prayer asking God's help as part of a religious service
(law) a defendant's answer by a factual matter (as distinguished from a demurrer)	a humble request for help from someone in authority