This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 挊 is uncertain. It visually contains 扌 (hand) and a right side that resembles 卜 over 一, but the origin of this combination is unclear.
With no clear meaning, focus on the shape: a hand 扌 beside a divination rod 卜 over a single line 一. Imagine a hand fiddling with a rod and a line, like someone idly toying with objects.
For ロウ, picture a hand 扌 rowing a boat with a single oar (卜 over 一): row -> ロウ, as the hand moves the oar back and forth.