(informal) Used with an arbitrary number to describe a person who looks or feels very bad.

plural of available seat-mile

A basic unit used by transport companies for calculating profit levels etc. It is calculated by multiplying total distance travelled in a given period by the number of passengers.

A length of one nautical mile, the limits of which have been accurately measured and are indicated by ranges ashore. It is used by ships to calibrate logs, revolution counters, etc. as well as to measure the ship's speed.

(chiefly US) Given that one is partly involved in or committed to a project, action, position, etc., there is no reason to refrain from becoming fully involved or fully committed.

A distance in international athletics (particularly track), the 1500 meter race, being about a mile (~1609 meters).

A unit of distance for air transport; equal to a nautical mile.

the City of London

An ancient Roman unit of itinerant distance of 1000 paces (mille passus, hence also "mile" from Latin mille, "1000"). Indirectly standardized to 5000 Roman feet by Agrippa in 29 BC. In modern times, Agrippa's Imperial Roman mile is empirically estimated to have been around 1481 meters (1620 yards, 4860 English feet, 0.92 English miles); compared with a modern mile, which is 5280 feet.

a nautical mile