(arch.) place in eastern Shandong
琊 is an archaic kanji used in a historical place name in eastern Shandong. Its standalone meaning is unclear outside that context.
琊 combines 王 (jade) with 邪, which likely contributes the sound. It is primarily used in the ancient place name 琅琊 (Langya).
The jade radical 王 suggests a precious or geographical marker, and 邪 gives the sound. Picture a jade tablet marking the ancient Langya region.
For ヤ, imagine a yak standing in the ancient Langya region: yak -> ヤ, and the jade tablet marks the spot.
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