mid-15c., "elapsing of time, expiration;" also "temporary forfeiture of a legal right" due to some failure or non-action by the holder, from Old French laps "lapse," from Latin lapsus "a slipping and falling, a landslide; flight (of time); falling into error," from labi "to glide, slip, slide, sink, fall; decline, go to ruin," which is of unknown etymology.
Meaning "moral transgression, sin" is from c. 1500; that of "slip of the memory" is 1520s; that of "a falling away from one's faith" is from 1650s.
"fall down or out," chiefly medical, 1736, from Latin prolapsus, past participle of prolabi "glide forward, slide along, slip forward or down;" see pro- "forward" + lapse (n.). As a noun, "a falling down of some part of the body," from 1808. Prolapsion in a theological sense, in reference to a falling into sin, is from c. 1600.
"to slide, slip, or glide away; pass away with or as if with a continuous gliding motion," used of time, 1640s, from French elapser, from Latin elapsus, past participle of elabi "slip or glide away, escape," from ex "out, out of, away" (see ex-) + labi "to slip, glide" (see lapse (n.)). The noun now corresponding to elapse is lapse, but elapse (n.) was in recent use. Related: Elapsed; elapsing.
[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]