I dont know there are plenty names in Latvia that are not understandable I dont know greek so I cant tell just by looking in map If you are realy interested here is lakes of Latgale in tour guide and database of lakes in Latvia both are in Latvian but I think youll get the idea in the last site there are three search fields on the top  from top to bottom first field is exact name it will sugest you names as you type second is part of name so you can enter root you are looking for and the last one is adminstrative regions