"Buy the farm" is an English idiom used as a colorful way of saying that someone has died. The phrase was first popularly used in the 20th century concerning soldiers who had perished in battle. A colorful expression that undercuts the solemnity of death, "buy the farm" has since been expanded through popular usage to include anyone who has died under any circumstances. Its origins are somewhat unclear, but it is generally associated with the connection between soldiers in battle and their intentions to settle down after the war.
There are many occasions when people use idioms as a colorful way of expressing an otherwise mundane thought. An idiom is a phrase that gains a meaning separate from its literal meaning when it is used often by people in a culture. Many of these idioms are used to express that someone has died, providing a type of gallows humor to lessen the seriousness of the occasion. One of the most popular of these phrases is "buy the farm."
The phrase "buy the farm" is one particular idiom where the literal meaning of the words diverges wildly from the accepted meaning of the phrase. Buying a farm would seem to be a peaceful and prosperous occasion in someone's life and not something to be feared like death. But, as is so often the case with idioms, the phrase grew out of somewhat murky origins to be accepted as shorthand for something totally different from the literal meaning of the words. An example would be someone saying, "I never thought he would buy the farm so young, since he seemed so healthy."
Many possible explanations exist for the origin of this particular phrase. The most sensible of these seems to be the fact that many soldiers fighting in wars in the middle of the 20th century had hopes and dreams of coming back home after the war and settling down to a simple life. Buying a farm would be the epitome of such a simple life, and soldiers who died in battle were said to have "bought the farm" for good.
Other explanations have arisen for the origin of the phrase. These range from the policy of farmers receiving insurance settlements when airplanes crashed on their property to the practice of a soldier's family receiving payments from the government if the soldier dies in battle, money which could conceivably be used to buy a farm. No matter the origin, the phrase "buy the farm" has expanded well beyond its military connections.