Anhedral is a term often used in geology and mineralogy to describe a mineral or crystal face that is not flat or parallel to its symmetry planes. The opposite of anhedral is euhedral, which refers to a crystal or mineral that has well-formed faces with distinct, sharp edges, and flat planes. Other antonyms for anhedral include: symmetrical, regular, uniform, even, level, and parallelogrammic. These terms all describe shapes that are smooth, flat, and regular. In contrast, anhedral shapes are irregular, jagged, and rough, reflecting their origins in chaotic, unpredictable environments like volcanic eruptions, earthquakes, and meteor impacts.