(1) (Through Fr. querelle from Lat. querela, complaint), originally a complaint against a person, particularly a legal accusation or charge, hence a ground or cause for complaint or anger, or, more generally, an outbreak of anger or violent dispute. (2) (Through O. Fr. quarrel or quarel, from med. Lat. quadrellus, diminutive of quadrus, square), a heavy short bolt or arrow with a square head, used in a cross-bow or arbalest. In architecture this term (and also the doublet "quarry") is applied to any square-shaped opening, in the Beauchamp Roll to the quatrefoils in Perpendicular windows, sometimes to squares of paving, but most commonly to the lozenge-shaped pieces of glass in lead casements (see Glass, Stained) .