Definition of last mile in US English:

last mile

noun

  • 1(In transportation contexts) the distance from a central depot or other offloading point to the final delivery destination (frequently considered as involving greater difficulty or costs).

  • 2Telecommunications the cabling or wireless technology that connects an end user to the Internet, typically having slower transmission speeds or being more expensive to maintain than other parts of the network; frequently attributive.

Origin

1970s; earliest use found in Translog.