infra (adv.)

word-forming element meaning "below, beneath," from Latin infra (adverb and preposition) "below, underneath, on the under side, beneath," also "later than; smaller than; inferior to," related to infernus "low, below," from PIE *ndher "under" (source also of Sanskrit adnah "below," Old English under "under, among;" see under). Modern popular use of it dates from the 1920s, as an opposite to super-, often in science fiction. "This use of infra- is scarcely a Latin one" [OED].

1731, from infra- + Latin lapsus "a fall" (see lapse (n.)) + ending from unitarian, etc.

[In theology], the doctrine held by Augustinians and by many Calvinists, that God planned the creation, permitted the fall, elected a chosen number, planned their redemption, and suffered the remainder to be eternally punished. The Sublapsarians believe that God did not permit but foresaw the fall, while the Supralapsarians hold that God not only permitted but decreed it. [Century Dictionary]