This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 跈 is uncertain. It combines 足 (foot) with 㐱, but the origin and original meaning are unclear.
Since the meaning is unclear, focus on the shape: 足 (foot) beside 㐱. Imagine a foot stepping on something mysterious.
For デン, picture a den where a foot (足) steps on a mysterious object (㐱): den -> デン.