hoe
耨 centers on a farming tool used for breaking up soil and removing weeds: a hoe. Its meaning is concrete and specific to agricultural work.
耨 combines 耒 (a farming tool or plow) with 辱, which likely contributes the sound. The character originally referred to a weeding hoe used in agriculture.
The left side 耒 represents a farming tool, and the right side 辱 looks like a hand holding a tool over the ground. Picture a farmer using this tool as a hoe to break up soil and remove weeds.
For ドウ, imagine a farmer using a hoe while humming a low, rhythmic 'doh' sound with each swing: 'doh' -> ドウ, and the hoe digs into the earth.