Supplication
WordNet
noun
(1) The act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)
"The priest sank to his knees in prayer"
(2) A humble request for help from someone in authority
(3) A prayer asking God's help as part of a religious service
WiktionaryText
Etymology
From Old French supplication, from Latin supplicatio, from supplicare ‘to supplicate’.