infra-

1.
a prefix meaning “below,” used, with second elements of any origin, in the formation of compound words:
infrasonic; infrared.
Origin
< Latin, representing infrā, adv. or preposition
British Dictionary definitions for infra-

infra-

prefix
1.
below; beneath; after: infrasonic, infralapsarian
Word Origin
from Latin infrā
Word Origin and History for infra-

word-forming element from Latin infra (adv., prep.) "below, underneath, beneath; later than, smaller, inferior to," from PIE *ndher "under" (cf. Sanskrit adnah "below," Old English under "under, among;" see under). Opposed to super-. Its use as a prefix was rare in Latin.

infra- in Medicine

infra- pref.
Inferior to, below, or beneath: infrasonic.