long
籊 centers on the idea of length, specifically describing something long and slender, like a tall bamboo stalk.
籊 combines 竹 (bamboo) with 翟, which likely contributes the sound. The character is used to describe something long, possibly originally referring to a long bamboo pole.
The bamboo top 竹 sits above 翟, like a tall bamboo stalk rising high. Picture a long, slender bamboo shoot stretching upward.
For テキ, imagine a long bamboo pole used as a tek (a made-up unit of length): tek -> テキ, and the pole is exactly one tek long.
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