Root ن ك ث(n k v) has 5 unique word forms and appears 7 times in the Quran.

English gloss Break, Violate, Breach, Perfidious, Disloyal

Word Translation Occurrences
نَّكَثُوٓاْ they break, who broke 4
يَنكُثُونَ broke (their word), broke (the word) 4
أَنكَٰثٗا (into) untwisted strands 2
نَّكَثَ breaks (his oath) 2
يَنكُثُ he breaks 2