Texte d'origine - Latin - HEC EST CRUX TOUS MCEUC COND ET DONALDI FILLI...

Hi. These words appear on a large stone / cross from a churchyard. It has been translated as "This is the cross of Thomas McEachan and his son Donald" I do not comprehend how if this was all latin that the given translation could be correct. I think it may be a mixture of French and Latin? MCEUC COND may be MCEUCCOND

Thank you very much.