ˈpedēən, ˈpēd- noun
( plural ped·ia -dēə)
Etymology: New Latin, from Greek, plain, flat surface, from pedon ground; akin to Latin oppido thoroughly, Old Norse fet step, Sanskrit pada step, track, Latin ped-, pes foot — more at foot
: a form of crystal having only a single face and belonging to the rare asymmetric class of the triclinic system