lapse (v.) Look up lapse at Dictionary.com
early 15c., said to be from lapse (n.) or from Latin lapsare "to lose one's footing." Related: Lapsed; lapses; lapsing.
lapse (n.) Look up lapse at Dictionary.com
mid-15c., "elapsing of time, expiration;" also "temporary forfeiture of a legal right," from Middle French laps "lapse," from Latin lapsus "a slipping and falling, flight (of time), falling into error," from labi "to slip, slide, sink, fall; decline, go to ruin." Meaning "moral transgression, sin" is c. 1500; that of "slip of the memory" is 1520s; that of "a falling away from one's faith" is from 1650s.