'Mantra' definitions:

Definition of 'mantra'

From: WordNet
noun
A commonly repeated word or phrase; "she repeated `So pleased with how its going' at intervals like a mantra"
noun
(Sanskrit) literally a `sacred utterance' in Vedism; one of a collection of orally transmitted poetic hymns

Definition of 'Mantra'

From: GCIDE
  • Mantra \Man"tra\, n. [Skr.] A prayer; an invocation; a religious formula; a charm. [India] [1913 Webster]
  • Note: Among the Hindoos each caste and tribe has a mantra peculiar to itself; as, the mantra of the Brahmans. --Balfour (Cyc. of India). [1913 Webster]