(number theory, recreational mathematics) A magic square with the additional property that the broken diagonals also summate to the magic constant.

plural of Greco-Latin square

The superposition of two Latin squares such that the result is also a Latin square.

(physics) The root mean square of the velocities of all the molecules in a volume of gas; directly proportional to its temperature in the case of an ideal gas.

(idiomatic) Something or someone that does not fit well or at all; something that will not succeed as attempted, except possibly with much force and effort, or alteration of either the peg or the hole or both beyond recognition.

plural of square peg into a round hole

plural of square peg in a round hole

(slang, vulgar, derogatory) Absolutely nothing.

Alternative form of citation needed

(number theory, recreational mathematics) A magic square of order n containing the numbers 1 to n² and where each 2 × 2 subsquare sums to 2s, where s = n² + 1, and all pairs of integers distant n/2 along a (major) diagonal sum to s.