A regular graph that has as few vertices as possible for its girth.
The catcher's wire mask.
In killer sudoku puzzles, an irregularly-shaped group of cells that must contain a set of unique digits adding up to a certain total, in addition to the usual constraints of sudoku.
An automobile.
The area from which competitors throw a discus or hammer.
The passenger compartment of a lift.
The drum on which the rope is wound in a hoisting whim.
An outer framework of timber, enclosing something within it.
Something that hinders freedom.
The goal.
An enclosure made of bars, normally to hold animals.
A skeleton frame to limit the motion of a loose piece, such as a ball valve.
A wirework strainer, used in connection with pumps and pipes.
To immobilize an artificial horizon.
To restrict someone's movement or creativity.
To confine in a cage; to put into and keep in a cage.
To track individual responses to direct mail, either (advertising) to maintain and develop mailing lists or (politics) to identify people who are not eligible to vote because they do not reside at the registered addresses.
A geometric shape with four angles and four straight sides; a four-sided polygon.
The buildings forming the border of such a courtyard.
A courtyard which is quadrangular.