inchworm, geometer
蠖 centers on a specific type of caterpillar: the inchworm or geometer moth larva, known for its looping movement.
蠖 combines 虫 (insect) with 蒦, which likely contributes the sound. The character specifically names the inchworm.
The insect radical 虫 on the left tells you it's a bug, and the right side 蒦 looks like a complex measuring tool—picture an inchworm measuring its way along a branch.
For ワク, imagine an inchworm inching along a wok: wok -> ワク, and the worm loops around the curved pan.
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geometer moth caterpillar; geometrid caterpillar (of subfamily Ennominae)