buy the farm

Not known with certainty. Two long-held hypotheses are as follows: One describes combat soldiers wistfully wishing to go back home, buy a farm, and live peacefully there; later, after they had been killed in combat, their fellow soldiers would say that they had bought the farm (compare the established metaphor pattern of having gone to that big [whatever sort of nice place] in the sky). Another links the phrase to the idea that governments compensate farmers whose land is damaged by a military aircraft crash; a deceased pilot was thus said to have bought the farm, and the term eventually entered wider use. Still another links it to a sardonic attitude of farmers that farms are often so heavily mortgaged and farmers' finances so difficult that one could not finish buying one's farm until one was dead.