A plesiohedron is the Voronoi cell of a so-called symmetric Delone set. Plesiohedra are space-filling polyhedra which have special symmetries that take any copy of the plesiohedron in the space-filling honeycomb to any other.
The five parallelohedra are plesiohedra, as are the triangular prism, plesiohedral gyrobifastigium, triakis truncated tetrahedron, and trapezo-rhombic dodecahedron.
Other plesiohedra include the 17-sided Voronoi cells of the Laves graph and two 38-faced polyhedra Engel polyhedra, one of which is illustrated above (Pegg 2022). The latter are known to have the largest possible number of faces for a plesiohedron (Schmitt 2016).
