This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 戓 is uncertain. It visually combines 戈 (halberd) and 口 (mouth), but the original semantic or phonetic role of these components is unclear.
With no clear meaning, picture a halberd 戈 beside a mouth 口, like a guard silently watching. The image is open-ended, matching the uncertain meaning.
For カ, imagine a car カ parked beside the halberd and mouth: car -> カ, a simple sound hook for this rare kanji.
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