cliff, ledge, bank, step
磡 centers on a steep rocky feature: a cliff, ledge, or bank, and by extension a step-like formation in stone.
磡 combines 石 (stone) with 勘, which likely contributes the sound. The character is used for rocky landforms such as cliffs and ledges.
The left side 石 means stone, and the right side 勘 suggests investigation. Imagine a geologist investigating a steep stone cliff, carefully examining the rocky ledge.
For カン, picture a can sitting on a stone ledge: can -> カン, and the can is perched on the cliff.
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