This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
舴 combines 舟 (boat) with 乍, which likely contributes the sound. The exact historical development is uncertain.
A boat 舟 with a distinctive right side 乍. Since the meaning is uncertain, picture a small boat with an unusual nameplate that reads '乍'.
For タク, imagine a small boat being tugged by a larger ship: tug -> タク, and the boat 舴 is pulled along.
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