Pentahedral refers to a solid or object with five flat faces or sides. Synonyms for this word include five-sided, quintangular, pyramidal, and polyhedral. Other options include quinquangular, pentagonal, pentahedric, and dipyramid. These words can be used interchangeably to describe shapes such as the pentagonal pyramid, which has a base with five sides and five triangular faces tapering up to a point at the top. Whether describing a geometric structure or a building with a distinct pentahedral shape, these synonyms can help to clarify and enhance the language used to describe the object in question.