to change, to alter, to accommodate oneself to
恑 centers on change and adaptation, especially adjusting oneself to circumstances. The idea of altering or changing is the core, with accommodating oneself as a natural extension.
恑 combines 忄 (heart/mind) with 危, which likely contributes the sound and may relate to danger or precariousness. The exact historical development is uncertain, but the character likely expressed a mental state of change or adaptation.
The heart radical 忄 beside 危 (danger) suggests a mind adapting to a precarious situation. When things are dangerous, you must change and accommodate yourself to survive.
For キ, imagine a key that changes shape to fit different locks: key -> キ, and your mind adapts like the key.