To open s.t. fastened (as buttons, zippers, buckles, strings); to undo s.t. (as bow, belt, sewing, etc.).
Undo the rope of that carabao.
I opened the string of the box.
I cannot open the fastening of my blouse.
Lekkahun la'itan badju'nu iyan; iyu' ga'i hāp.
Undo the sewing of your blouse; it is not good.