Dak /(da̤k [or] däk)/

Dak

n.
  1. Post; mail; also, the mail or postal arrangements; -- spelt also dawk, and dauk. [India]

Phrases & Compounds
Dak boat
a mail boat.
Dak bungalow
a traveler's rest-house at the end of a dak stage.
To travel by dak
to travel by relays of palanquins or other carriage, as fast as the post along a road.