An angle or space which cannot be seen or defended from behind the parapet of a fortification.

angle brace

(geometry) The angle formed by two rays of light, or two straight lines drawn from the extreme points of an object to the center of the eye.

(architecture) A square rod of wood standing flush with the wall on each of its sides, at the external angles of plastering, to prevent their being damaged.

(architecture) A detail in the form of a leaf, more or less conventionalized, used to decorate and sometimes to strengthen an angle.

(architecture) A bead worked on or fixed to the angle of any architectural work, especially for protecting an angle of a wall.

(architecture) An enriched angle bead, often having a capital or base, or both.

(carpentry) A brace across an interior angle of a wooden frame, forming the hypotenuse and securing the two side pieces together.

(mathematics, geometry) An angle measuring less than ninety degrees.

(mathematics, geometry) An angle that is greater than 90 degrees and less than 180 degrees.