Was heißt assurance? Was heißt assurance? The act of assuring.A statement or indication that inspires confidence; a guarantee or pledge: gave her assurance that the plan would succeed. Freedom from doubt; certainty: set sail in the assurance of favorable winds. See Synonyms at certainty.Self-confidence. See Synonyms at confidence.Excessive self-confidence; presumption.Chiefly British Insurance, especially life insurance.