IPA: //ʌnˈtæk//
KK: /ʌnˈtæk/
To take off or remove the tack (equipment) from a horse.
After the ride, she decided to untack the horse and put away the equipment.
Past: untacked
Past Participle: untacked
Untack → It is formed from "un-" (meaning not or opposite of) and "tack" (from Old English *tacan*, meaning to fasten or attach). The word "untack" means to remove or take off something that has been fastened or attached.
Think of 'un-' meaning not or the opposite, and 'tack' meaning to fasten. So, when you untack something, you are doing the opposite of fastening it.