FLANK, in Fortification, is a line drawn from the extremity of the face towards the inside of the work. Or, flank is that part of a bastion which reaches from the curtain to the face, and defends the opposite face, the flank, and the curtain.
Flickant FLANK is that whence a cannon playing fires directly on the face of the opposite bastion.
Rasant or Razzant FLANK is the point whence the line of defence begins, from the conjunction of which with the curtain the shot only rases the face of the next bastion; and this happens when the face cannot be discovered but from the flank alone.