son-in-law
From Proto-Italic *genros, from Proto-Indo-European *ǵm̥ros, from Proto-Indo-European *ǵem-. The current form can be derived from a byform *gemros, assimilating the nasal to make *genros, from which derives a second-declension r-stem.
Practice speaking and memorizing "gener" and many other words and sentences in Latin.