1) Any clay rock 2) Sedimentary rock 
(Greek Pelos, Clay)
Pelite (Greek pelos, clay) is an old and currently not widely used field geological term for a clayey fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone. It is equivalent to the Latin-derived term lutite. More commonly, metamorphic geologists currently use pelite for a metamorphosed fine-grained sedimentary rock, i.e. mudsto...
pelite A sediment or sedimentary rock composed of fine fragments; such as, clay or mud.