nounpl. -·drons or -·dra
Origin of tetrahedronModern Latin from neuter of Late Greek tetraedros, four-sided: see tetra- and -hedron
nounpl. tet·ra·he·drons, or tet·ra·he·dra
Origin of tetrahedronGreek tetraedron from neuter of tetraedros four-faced tetra- tetra- -hedros sided ; see -hedron .
(plural tetrahedrons or tetrahedra)
From Ancient Greek Ï„ÎµÏ„ÏÎ¬ÎµÎ´ÏÏŒÎ½ (tetraedron, “triangle-based pyramid"), from Ï„ÎµÏ„ÏÎ¬ÎµÎ´ÏÏŒÏ‚, from Ï„ÎµÏ„ÏÎ¬Ï‚ (tetras, “four") + á¼•Î´ÏÎ± (hedra, “seat").