This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 奟 is uncertain. It visually combines 大 (big) on top and 朋 (companion) below, but this may be a later formation or a variant of another character.
Since the meaning is unclear, a mnemonic is not possible. Focus on remembering its shape: 大 (big) over 朋 (companion).
For コウ, imagine a big (大) companion (朋) named Kou: Kou -> コウ. Picture a large friend named Kou standing tall.
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