pig's head radical variant (no. 58)
彑 is a rare variant form of the pig's head radical (no. 58). Its standalone meaning is limited to this radical sense and it is not used as an independent character in modern Japanese.
彑 is a variant form of the pig's head radical (⺕/彐). It originated as a pictograph of a pig's head, but the exact historical development of this particular variant is uncertain.
The shape suggests a pig's snout and ears: the top horizontal line and the boxy shape below form the head, with a small stroke on the right like an ear. Think of it as a stylized pig's head.
For ケイ, imagine a pig named Kay who always sticks her head out first: Kay -> ケイ, and her head is the radical 彑.