KanjiJLPT N1
Lock

lock, fetters, shackles

Mnemonic

You determine that the treasure chest needs a lock made of pure gold. You melt gold bars, pour the molten metal into a lock-shaped mold, and once it cools into a gleaming lock, you determine a secret combination—sealing it in your memory alone.
Additional thoughts
Picture a shimmering golden padlock. The act of determining the combination is what makes it secure. Gold + Determine = Lock. The golden weight of it in your hand reinforces the image.
Quick recall
Determine a secret combination for a gold Lock.

Details

The keyword for 錠 is lock. This kanji refers to a locking mechanism or a device used to fasten and secure doors, gates, or containers, preventing them from being opened without a key. It conveys the idea of fastening something shut for safety or security. In addition to physical locks, the kanji is also used to refer to tablets or pills in pharmaceutical contexts, as their small, compact shape was likened to a lock's clasp.
On'yomi
じょう