Definitions for "Redan"
A work having two parapets whose faces unite so as to form a salient angle toward the enemy.
Smaller than a redoubt. A small field fortification with two walls set at a salient angle facing the enemy. The rear, or gorge, was usually open. A redan could be used to cover a camp, the front of a battlefield, advanced posts, bridges, or roads into a town. (same as a Fleche)
a work with two faces making a salient angle
Keywords:  ravelin, smaller
The same as a Ravelin, though somewhat smaller.
Keywords:  uneven, offset, vertical, step, ground
A step or vertical offset in a wall on uneven ground, to keep the parts level.