ratline

Short definition from Wiktionary

Noun

1. 1
   The rope or similar material used to make cross-ropes on a ship.
2. 2
   Any of the cross ropes between the shrouds, which form a net-like ropework, allowing sailors to climb up towards the top of the mast.
3. 3
   A system of escape routes for Nazis and other fascists fleeing Europe in the aftermath of World War II.