Before revision: A semi-circular bund or demi lune is a rainwater harvesting technique consisting in digging semilunar holes in the ground with the opening perpendicular to the flow of water.
After revision: A semi-circular bund (also known as a demi-lune or half-moon) is a rainwater harvesting technique consisting in digging semilunar holes in the ground with the opening perpendicular to the flow of water.