D defs.my
Entry 1 sense Webster, 1913

Cata

· Cat·a · IPA
01 The Latin and English form of a Greek preposition, used as a prefix to signify down, downward, under, against, contrary or opposed to, whol…
  1. 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.