Indentation, characterized as a cut or a dent in a surface can be contrasted with many antonyms. A rise or protuberance, such as a bump or a bulge, would stand in opposition to indentation. Smoothness, flatness, and levelness would also be antonyms, as would elevation, prominence, and projection. Other antonymic terms for indentation could include convexity, hump, lump, and mound. In essence, any word describing a shape or texture that is the diametrical opposite of a cut or recess would be an apt antonym.