Unbutton/ˌʌnˈbʌtn/ Definition 1 of 2Pro Tip 1/3Physical Action Indicates a deliberate physical movement to open clothing, often for comfort or practical reasons. She unbuttoned her coat as she stepped indoors. Pro Tip 2/3Initial Step Sometimes the first step before removing an article of clothing entirely. He started to unbutton his jacket before taking it off. Pro Tip 3/3Preparation for Comfort Can signify the start of relaxation in a more private or informal setting. After work, I unbutton my collar to relax.