collapse v.

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.

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.