desatacar

An old-fashioned or regional verb meaning to unfasten or loosen clothing — undoing buttons, belts, or laces: desatacarse los pantalones, "to undo one's trousers." It comes from atacar in its older sense of "to fasten/lace up," unrelated to the modern military meaning of atacar (to attack).

• Se desatacó el cinturón después de comer tanto. — He loosened his belt after eating so much.
• El niño no sabía desatacarse los botones. — The boy didn't know how to undo his buttons.
• Se desatacó los pantalones para estar más cómodo. — He undid his trousers to be more comfortable.

Don't confuse this with the everyday atacar (to attack) — desatacar comes from an older, unrelated sense of atacar meaning "to fasten/lace," not the aggressive meaning; desabrochar is the everyday modern word for "to unbutton/unfasten."

Often confused with desabrochar.