This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
晘 combines 日 (sun) with 旱 (drought). The exact historical development is uncertain, but it likely relates to sunlight or dryness.
The sun 日 beside drought 旱 suggests a harsh, dry sunlight. Without a clear meaning, picture a sun so intense it causes drought.
For カン, imagine a can of water under the scorching sun: can -> カン, desperately needed during the drought.
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