"The men's cats"
Translation:Cait na bhfear
To be exact, the eclipsis is caused by the definitive article preceding the genitive noun. If the noun and the article were in the nominative case, on the other hand, no ecclipsis would be caused. Since both npl. and gpl. of the definite article are "na", we can only recognize the genitive by recognizing the ecclipsed noun.