Archaic form of rule the roost.

(engineering) A knuckle joint having shoulders that abut when the connected pieces come into line with each other, and thus permit folding in one direction only.

(printing, historical) A thin slip of brass or steel, against which the type is arranged in a composing stick, or by the aid of which stickfuls or handfuls or type are lifted.

(calculus) A formula for computing the derivative of the functional composition of two or more functions.

A scale marked with numbers for finding without calculation the number of square feet in a board.

(printing, historical) A fine, thin, short metal rule of the same height as the type, used in printing short lines in tabular matter.

Ampère's circuital law

(rail transport) The steepest uphill gradient in one direction on a section of railway line, which determines the load that can be pulled by one locomotive over that section, according to the power rating of the locomotive. A typical ruling gradient could be 1:50 (2%). The ruling gradient can differ in the other direction on the same section.

The recommendation that a person should drink eight servings of eight ounces of water each day.

plural of ruling gradient