offside rule

The computer-programming sense was coined by British computer scientist Peter Landin in 1966 and named after the rule in football (soccer).

1(various team sports) The rule determining whether a player is in an offside position; that is, an illegal position ahead of the ball, puck, etc.
2traffic engineeringA system that gives right-of-way at an intersection to traffic approaching from the side on which one is not driving.
3(programming) In some programming languages, the convention by which the indentation of a line of source code affects its meaning.