A cusec is a unit to measure distance used by the inhabitants of Taurus II, in the Taurean system.
When it was discovered that the landing party from the USS Enterprise (NCC-1701) was hidden in a giant urn that was filling with rain water, Theela noted that the nearest water accumulation was many cusecs from the main compound. (TAS: "The Lorelei Signal")
- No indication is given on how far is a cosek, but one must assume as being a considerable distance as a kilometer or a mile.