kind of slug
蛞 centers on a specific kind of slug, a soft-bodied terrestrial mollusk. The meaning is narrow and refers to this animal.
蛞 combines 虫 (insect/worm) with 舌 (tongue), likely as a phono-semantic compound where 舌 contributes the sound and 虫 indicates a small creature. The exact historical development is uncertain.
The left side 虫 suggests a small crawling creature, and the right side 舌 looks like a tongue. Imagine a slug stretching out its tongue-like body as it moves.
For カツ, picture a slug slowly crossing a cut (カツ) piece of lettuce: cut -> カツ, and the slug is the kind of creature that might be found there.
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