Perhaps from Proto-Indo-European *neik- (“to attack, start vehemently”) and cognate with Lithuanian ap-ni̇̀kti (“to attack”), su-ni̇̀kti (“to attack”), Latvian nikns (“bad, grim, vehement”), maybe also Russian в-никнуть (v-niknutʹ), про-никнуть (pro-niknutʹ). See also νίκη (níkē).
νεῖκος • (neîkos) (genitive νείκους) n, third declension
- quarrel, wrangle, strife
- strife of words, railing, abuse, taunt, reproach
- strife of law, dispute before a judge
- battle, fight
This inflection pattern originally had a sigma (i.e. νείκεσος), which was dropped early on in the history of Ancient Greek.
The irregular accentuation of this paradigm is explained by the fact that it is the contracted version of the above paradigm.
- LSJ 8th edition
- Robert S. P. Beekes (2010) Etymological Dictionary of Greek, Leiden, Boston: Brill Academic Publishers