Dictionary
in•fra
Pronunciation: (in'fru), [key]—
adv.
below, esp. when used in referring to parts of a text. Cf.
supra.infra-
a prefix meaning “below,” used, with second elements of any origin, in the formation of compound words:
infrasonic; infrared. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.