emaciated
窶 centers on the state of being severely thin and wasted away: emaciated, gaunt, or haggard from illness or hardship.
窶 combines 穴 (hole, cavity) with 婁, which likely contributes the sound and may relate to the idea of being hollow or wasted. The exact historical development is uncertain.
Imagine a person so thin that their body looks like a hollow cave (穴) with a gaunt, skeletal figure (婁) inside. The cave-like emptiness shows how emaciated they are.
For ロウ, picture a low, hollow cave where someone has become emaciated: low -> ロウ, and the cave (穴) shows their wasted state.