Definition of "gangplank"
(nautical) A board used as a temporary footbridge between a ship and a dockside.
Quotations
Every since the age of six Troy Belknap of New York had embarked for Europe every June on the fastest steamer of one of the most expensive lines. With his family he had descended at the dock from a large noiseless motor, had kissed his father good-bye, turned back to shake hands with the chauffeur (a particular friend), and trotted up the gang-plank behind his mother's maid, [...]
1918, Edith Wharton, chapter I, in The Marne, New York, N.Y.: D[aniel] Appleton and Company, page 1