This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
襺 combines 衤 (clothing) with 繭 (cocoon). The exact historical development is uncertain, but it likely relates to padded or layered clothing, possibly associated with the idea of a cocoon.
The clothing radical 衤 beside 繭 (cocoon) suggests a garment that wraps like a cocoon, perhaps a padded robe.
For ケン, imagine a ken (a traditional Japanese garment) wrapped around you like a cocoon: ken -> ケン.