In The Search for Spock and The Final Frontier, the respective bridge officers of Captain Kruge and Captain Klaa's ships use "kellikams" (perhaps "kellicams") as a unit of distance in space. An example usage might be:
20,000 kellikams and closing!
The unit may have also been used in some episodes of the TNG-era series (perhaps the DS9 episode "Once More unto the Breach", before, during, or after the raid on Trelka V's Dominion outpost).
Can anyone provide a reference for converting 1 kellikam to a Terran unit?