カン, ケン, かわ.く, かわ.かす, ほ.す, ひ.る, いぬい
drought, dry, dessicate, drink up, heaven, emperor
JLPT2 G7 S11 F1453
The relevant bronzeware inscription form is 乙 (rise) + an element# combining 日 sun/day and a pennant/banner → the sun likened to a flag that rises high in and adheres to the sky → *high and bright sky* → *dry* (← air/water that rises due to heat).
[Full Kanji Etymology List]