unbutton
UK: ʌnˈbʌtn | US: ʌnˈbʌtn
vt. to unfasten or open by releasing buttons
vi. to become unfastened by the release of buttons
The word "unbutton" combines the prefix "un-" (Old English "un-," meaning "not" or "reverse action") with "button" (Old French "boton," meaning "knob" or "fastener"). The prefix "un-" negates or reverses the action of the root, turning "fasten a button" into "undo a button." This logical construction reflects a straightforward reversal of the verb's original meaning, a common pattern in English (e.g., "lock" → "unlock").
She quickly unbuttoned her coat as she stepped indoors.
The toddler tried to unbutton his shirt but couldn’t manage the small buttons.
The dress was designed to unbutton at the back for ease of wearing.
He unbuttoned his collar to feel more comfortable in the heat.
The jacket will unbutton if you pull too hard on the fabric.