What would you call a pleading before a judge or God [closed]

Is there a noun or adjective for the following or similar:

• a pleading before a judge for clemency
• a prayer before God begging for mercy

Is there a better word than "begging", "pleading", "petitioning", etc.?

Judge or God, clemency or mercy..

Supplication, a noun, can logically be applied to any situation in which you plead to someone in power for help or a favor.

Supplication: comes from the Latin verb supplicare, which means "to plead humbly." (etymonline.com)

Supplication (also known as petitioning) is a form of prayer, wherein one party humbly or earnestly asks another party to provide something, either for the party who is doing the supplicating (e.g., "Please spare my life.") or on behalf of someone else (e.g., "Please spare my child's life.").
(wiki)

Prayer may be best because it is actually a legal term of art. E.g., I'm looking at a court order that reads "... it is hereby ORDERED and DECREED that the prayer of the Petition is DENIED...."

Perhaps entreaty

An earnest or humble request: the king turned a deaf ear to his entreaties

Oxford Dictionaries Online

The noun imploration might be suitable to your needs.

An act of begging someone to do something:
earnest implorations for divine forgiveness and mercy

From the verb implore Etymonline tells us

v. c.1500, from Middle French implorer and directly from Latin implorare "call for help, beseech," originally "invoke with weeping," from assimilated form of in- "on, upon" + plorare "to weep, cry out." Related: Implored ; imploring ; imploringly.

In the English criminal courts the defence, between conviction and sentencing, may make a plea in mitigation.