KanjiJLPT N2
Contraption

contraption, fetter, machine, instrument

Mnemonic

Carved into an ancient tree is a commandment: "THOU SHALT BUILD." Obeying, you gather branches, lash them with vines, add levers and pulleys—until the tree itself transforms into a magnificent contraption of spinning gears and creaking wooden cogs, alive with motion.
Additional thoughts
Picture a living tree whose trunk splits open to reveal interlocking wooden gears inside, with a commandment tablet nailed to its bark like a blueprint. The tree IS the machine.
Quick recall
A tree bearing a commandment to build becomes a living wooden contraption.

Details

The keyword for 械 is contraption. This kanji refers to mechanical devices, instruments, or apparatus—things built with interlocking parts to serve a specific function. It carries a sense of something constructed or engineered, often with an implication of complexity or ingenuity. It is most commonly encountered in the compound for "machine" or "machinery," emphasizing the idea of a purposefully assembled mechanism.
On'yomi
かい
Kun'yomi
かせ

Used in vocab