The Collaborative International Dictionary of English v.0.48:

Permian \Per"mi*an\, prop. a. [From the ancient kingdom of
   Permia, where the Permian formation exists.] (Geol.)
   Belonging or relating to the period, and also to the
   formation, next following the Carboniferous, and regarded as
   closing the Carboniferous age and Paleozoic era. -- n. The
   Permian period. See Chart of Geology.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Permians \Per"mi*ans\, n. pl.; sing. Permian. (Ethnol.)
   A tribe belonging to the Finnic race, and inhabiting a
   portion of Russia.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Permian
    n 1: from 280 million to 230 million years ago; reptiles [syn:
         Permian, Permian period]