This is the 275th most frequent Slovak word.
rokmi
"Rokmi" means "by years" or "over the years" in English.
In this sentence, 'rokmi' is used in its instrumental plural form to indicate a time period in the past.
Pred rokmi sme boli na výlete v Tatrách.
Years ago, we went on a trip to the Tatras.
Here, 'rokov' (genitive plural) is used in the phrase 'odstupom rokov' to indicate a period over which change or perspective has occurred. Though not 'rokmi', its contextual usage clarifies its relation.
S odstupom rokov vidíme veci jasnejšie.
With the passing of years, we see things more clearly.
In this case, 'roky' is used in its nominative plural form to denote a specific quantity of years, a time measurement.