(cricket) A fielding position on the leg side, square of the batsman's wicket; a fielder in that position.

(cricket) The umpire who stands at or near square leg to rule on decisions at the batsman's end of the wicket. In some circumstances, the umpire may stand at the equivalent position on the opposite side of the batsman (between gully and point), but is still referred to as the square leg umpire in these circumstances.

(idiomatic) Located back at the start, as after a dead end or failure.

(idiomatic) Back to the start, as after a dead end or failure.

The form of writing used in ancient Rome for inscriptions.

(mathematics, of a set of numbers or values) The square root of the arithmetic mean of the squares.

(physics) any physical law, such as that of gravitation, in which a quantity varies inversely with distance from a source as the square of that distance

(algebra) The identity x²-y²=(x+y)(x-y), that holds for all real numbers.

(statistics) A probability distribution widely used in inferential statistics.

(mathematics) any statistical hypothesis test in which the test statistic has a chi-square distribution if the null hypothesis is true