Unbuckle/ˌʌnˈbʌkl/ Definition 1 of 2Pro Tip 1/3Physical Action Often implies a manual action of opening something that wraps around. After the meeting, he unbuckled his watch. Pro Tip 2/3Safety Context Commonly used with safety items, like seatbelts or helmets, emphasizing a release from security. The pilot reminded us to not unbuckle until safe. Pro Tip 3/3Casual Tone Usually casual, used in everyday situations, not typically formal. Please unbuckle your shoes and relax.