Flank
one of the two parts of the body which enable it to bend; the part of the side of an animal between the ribs and the hip. As a military term, either side of body of troops; a the extremities of a body of soldiers in line, or the sides of a column, being termed the right and left flanks respectively. In any defense work, it is applied to that part from which a fire may be directed against the side or flank of an attacking party. Thus, the flanks of a bastion are those parts of the rampart and parapet which connect its faces with the extremities of the curtains of the enceinte on either side of it. A fire from the flanks is effective in preventing an attacking party from effecting a lodgment at the foot of the curtain that FLANNAGAN lies between them, which might be done with comparative ease and security if these portions of the work did not exist.
A fire from the flanks of any bastion enfilades the ditch at the foot of the curtain. In architecture, the side of any building.
In machinery, the straight part of the tooth of a wheel which receives the impulse. Flanks, in farriery, a wrench, strain, or other injury received by a horse in the back.