cata-

1. a prefix meaning “down,” “against,” “back,” occurring originally in loanwords from Greek (cataclysm; catalog; catalepsy); on this model, used in the formation of other compound words (catagenesis; cataphyll).

prefix

1. down; downwards; lower in positioncatadromous; cataphyll
2. indicating reversal, opposition, degeneration, etccataplasia; catatonia

word-forming element from Latinized form of Greek kata-, before vowels kat-, from kata “down from, down to.” Its principal sense is “down,” but occasionally it has senses of “against” (catapult)or “wrongly” (catachresis). Also sometimes used as an intensive or with a sense of completion of action (catalogue). Very active in ancient Greek, this prefix is found in English mostly in words borrowed through Latin after c.1500.

pref.

1. Down:catabolism.
2. Reverse; backward; degenerative:cataplasia.