means A layover is a break in a journey, usually a stop between connecting flights, where you wait somewhere before continuing on to your final destination.

from A plain compound of 'lay' and 'over' — to 'lay over' somewhere meant to stop and stay temporarily before resuming travel, a phrasing that goes back to American travel and railroad talk in the 19th century. The verb phrase hardened into the noun 'layover' as train and then air travel made the unwanted pause a recognizable thing worth naming. It's cousin to 'stopover,' built on the same logic: you lay your journey over, set it aside, and pick it up again later.