to hang the head, to bow the head, to droop, to lower, low, beneath
仾 centers on lowering something physically or figuratively: hanging or bowing the head, drooping, or being in a low or beneath position.
仾 is a rare character. It combines 亻 (person) with 互, which may have contributed a phonetic element, but the exact historical development is uncertain.
A person 亻 beside 互, which looks like a lowered, drooping shape. Imagine someone bowing their head low, the posture matching the drooping form of 互.
For テイ, picture a person bowing so low that their head touches the table: table -> テイ, and the lowered head meets the surface.