defend, protect
捍 centers on active defense: guarding against harm, protecting something, or warding off an attack.
捍 combines 扌 (hand) with 旱, which likely contributes the sound and may relate to dryness or stopping, suggesting a hand that wards off or blocks. The exact historical development is uncertain.
The hand radical 扌 beside 旱 (which looks like a shield with a sun on top) suggests a hand holding a shield to defend and protect.
For カン, imagine a can of defensive spray: can -> カン, and your hand holds it to protect yourself.