Definitions for "Gangplank"
The narrow creaky tilting moving (usually wet and slippery) .... causeway for getting on and off the ship (usually).
A broad portable platform used to bridge the gap between the ship's deck, and the surface of a dock. Contrary to popular belief, having a sailor "Walk the Gangplank" would not be at all practical, as the weight of the plank would pull the apparatus off the ship. 'Walking the plank' is more a contemporary myth than a historical precedent. If a sailor was supposed to go overboard, most often they would simply be thrown over a waist-railing.
A flat, portable surface run between ship and dock or ship to ship for walking and transferring cargo.
a temporary bridge for getting on and off a vessel at dockside