to open out, to expand
挓 centers on the action of spreading or opening something out, like unfolding or expanding a physical object.
挓 is a phono-semantic compound: the hand radical 扌 suggests the action of opening or spreading, while 宅 likely contributes the sound タ. The exact historical development is uncertain.
The hand radical 扌 beside 宅 (house) suggests a hand opening the doors of a house wide, expanding the entrance.
For タ, imagine a hand opening a tall gate: tall -> タ, and the hand spreads the gate open.