Large stone or rock. A dorniker is a large stone that hinders your work in the field, work such as plowing or disking. It's not in any dictionary and seems to be a local term, not a made-up word on my part. Maybe someone has heard of it. Example: Rats, broke my blade on a dorniker again.
DORNIKER
Meaning of DORNIKER in English
Slang English vocab. Английский сленговый словарь. 2012