Buy The Farm Meaning

Example : 1959, Robert A. Heinlein, Starship Troopers[1], page 131:  You're just as dead if you buy the farm in an "incident" as if you buy it in a declared war.1984, G. Harry Stine, Manna[2], page 221:  Then tracers laced the sky in front of me. Forget the shooting! If I get distracted now, I'll buy the farm anyway!1995, Steve Allen, “Having a Good Time”, in Ann McDonough & Kent R. Brown, editor, A Grand Entrance[3], ISBN 087129933X, published 2000, page 212:  BETTY. Shoot, if I knew you was gonna buy the farm I coulda asked for everything you got in the world... How were you gonna do it? ¶ROGER (takes revolver out of briefcase). With this.2002, W. Barry Baird, Vietnam Journey[4], ISBN 0595226795, page 171:  They gambled with as much reckless abandon as they flew their airplanes. They knew they might buy the farm tomorrow.