to go, depart
厺 centers on the act of leaving or moving away: to go or depart. The given meanings are straightforward and share this single idea of departure.
厺 is a rare character whose exact historical development is uncertain. It visually combines 大 (big) and 厶 (private), but this may not reflect the original etymology.
Picture a big person (大) leaving a private place (厶) behind: 厺 means to go or depart.
For キョ, imagine a big person departing with a key (キョ) to lock the private place behind them: key -> キョ, and the person goes away.