DIOPTRIC

Cat´a


1. The Latin and English form of a Greek preposition, used as a prefix to signify down, downward, under, against, contrary or opposed to, wholly, completely; as in cataclysm, catarrh. It sometimes drops the final vowel, as in catoptric; and is sometimes changed to cath, as in cathartic, catholic.



Webster's Revised Unabridged Dictionary, published 1913 by C. & G. Merriam Co.