"One for the Road"

Meaning:

Last drink before I leave.

Origin:

The origin of 'one for the road' comes from the middle ages and medieval period. The phrase started in London with the criminals who were condemned to hang, on the day of their hanging they were taken to Tyburn hill for execution. On the way they stopped at a local inn situated on the road and were allowed 'one' drink. The 'one' drink that the ciminals were drinking was for the road to death.

Below: Tyburn Inn Public Execution