The Oxford Thesaurus An A-Z Dictionary of Synonyms - assurance n.

1) promise, pledge, guarantee or guaranty, warranty, commitment, bond, surety; word, word of honour, oath, vow: You have the bank's assurance that the money will be on deposit. 2) insurance, indemnity: His life assurance is barely enough to cover the costs of his funeral. 3) certainty, confidence, trust, faith, reassurance, surety, assuredness, certitude; security: There is no assurance that Herr Kleister will get the job done. 4 audacity, impudence, presumption, boldness, brazenness, nerve, effrontery, insolence , Colloq brass, gall, cheek, chutzpah: With an air of assurance they quote authors they have never read. 5) self-confidence, self-reliance, confidence, steadiness, intrepidity, self-possession, poise, aplomb, coolness, control, self-control, resolve, Colloq gumption, guts, gutsiness: He has the assurance of one born to command.