(roller derby) A player with responsibility for co-ordinating their team in a particular jam.
(computing) An element of a set to be sorted that is chosen as a midpoint, so as to divide the other elements into two groups to be dealt with recursively.
(mathematics) An element of a matrix that is used as a focus for rowoperations, such as dividing the row by the pivot, or adding multiples of the row to other rows making all other values in the pivot column 0.