My guess:
Metchroy means King of the Land.
From the root metch, meaning land/country in the Flaidish language and roy, meaning king.
Flaidish:
http://www.zompist.com/flaidish.htm
Metch:
http://www.zompist.com/flaidlex.htm
Unfortunately, Flaidish seems to be some made up alien language of the made up alien Flaidish people.