Assurance/əˈʃʊrəns/ Definition 1 of 3Pro Tip 1/3Reassurance Used when someone needs to be comforted or convinced about something. His mother's assurance calmed him before the exam. Pro Tip 2/3Commitment Indication Indicates a strong commitment to act or support. Her assurance of help made me feel supported. Pro Tip 3/3Strengthens Promises Often used to emphasize that a promise is solid and reliable. I need your assurance that you will deliver the project on time.