Translation guide
To undo or release something that is fastened, such as a button, buckle, belt, or knot. The most common Japanese expressions depend on what is being unfastened.
To undo a button, snap, or similar small fastener, typically on clothing.
General verb for removing or detaching something that is attached or fastened. Used for buttons, belts, accessories, etc.
Means 'to take off' and can be used for detachable items like brooches or clip-on accessories.
ブローチを取る
unfasten a brooch
To undo a belt, buckle, or similar strap-like fastener.
Same as above; the most common verb for unfastening belts and buckles.
ベルトを外す
unfasten a belt
バックルのベルトを外す
unfasten the buckle strap
Means 'to loosen'. Used when you want to relax the tension without completely removing, e.g., loosening a belt.
To undo a knot, bow, or tied string.
To open or release a mechanical fastener like a lock, latch, or hook.
Again the general verb for detaching or releasing something fastened.
鍵を外す
unfasten a lock (e.g., padlock from a hasp)
Means 'to open'. Used for locks that are opened with a key or combination, rather than physically detached.
錠を開ける
unfasten a lock (open it)
外す (hazusu) is the most versatile for unfastening things that are attached or hooked. 解く (hodoku) is specifically for untying knots or strings. 取る (toru) is for taking off detachable items. Use 外す when in doubt for buttons, belts, and clasps.
開ける (akeru) means 'to open' and is not used for unfastening clothing. Use 外す for buttons and zippers, or 脱ぐ (nugu) for taking off clothes entirely.
ベルトを緩める
loosen/unfasten a belt slightly
靴ひもがほどけた
My shoelaces came unfastened.