noun (n)

• a prayer asking God's help as part of a religious service(noun.communication)

  Synonym:
  invocation
  

  source: wordnet30
• a humble request for help from someone in authority(noun.communication)

  Synonym:
  plea
  

  source: wordnet30
• the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)(noun.act)

  Synonym:
  prayer
  

  source: wordnet30
• The act of supplicating; humble and earnest prayer, as in worship.(noun)

  source: webster1913