Search Result for "ordovician": 
Wordnet 3.0

NOUN (1)

1. from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds;
[syn: Ordovician, Ordovician period]


The Collaborative International Dictionary of English v.0.48:

Ordovician \Or`do*vi"cian\, a. [From L. Ordovices, a Celtic people in Wales.] (Geol.) Of or pertaining to a division of the Silurian formation, corresponding in general to the Lower Silurian of most authors, exclusive of the Cambrian. -- n. The Ordovician formation. [1913 Webster]
WordNet (r) 3.0 (2006):

Ordovician n 1: from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds [syn: Ordovician, Ordovician period]