1. of or pertaining to a hexagon: "small, hexagonal pockets of honeycomb"
▪ (of a solid) having a section that is a hexagon; constructed on a base that is a hexagon.
▪ designating or pertaining to a crystal system in which three coplanar axes of equal length are separated by 60° and a fourth axis of a different length is at right angles to these: "a hexagonal close-packed crystal structure"
▪ (of a mineral) crystallizing in a hexagonal system.