carpenter's plane, plane, level
刨 centers on a carpenter's tool for smoothing wood: a plane. The meanings 'plane', 'level', and 'carpenter's plane' all refer to this same tool or the action of planing.
刨 combines 包 (wrap, contain) with 刂 (knife). The exact historical development is uncertain, but it likely represents a cutting or scraping tool, consistent with the meaning of a carpenter's plane.
The left side 包 suggests something wrapped or contained, and the right side 刂 is a knife. Imagine a wrapped blade that shaves wood smooth: a carpenter's plane.
For ホウ, picture a carpenter planing a board and saying 'hoe!' as he pushes the plane forward: hoe -> ホウ.