\Draw"bridge`\, n.
A bridge of which either the whole or a part is made to be
raised up, let down, or drawn or turned aside, to admit or
hinder communication at pleasure, as before the gate of a
town or castle, or over a navigable river or canal.
Note: The movable portion, or draw, is called, specifically,
      a bascule, balance, or lifting bridge, a turning,
      swivel, or swing bridge, or a rolling bridge, according
      as it turns on a hinge vertically, or on a pivot
      horizontally, or is pushed on rollers.