This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
跔 combines 足 (foot) with 句, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side 足 suggests a foot or leg, and the right side 句 looks like a bent shape. Imagine a foot bending or crouching, but remember the meaning is uncertain.
For ク, picture a foot (足) bending into a cool, crouched pose: cool -> ク, but the foot is bent.