From G2095 (eu) and G5114 (teinō, to stretch). Literally 'well-stretched' — with full force, intensely.
Eutonōs describes both fury of opposition and power of proclamation. In Luke 23:10, scribes accused Jesus 'vehemently.' In Acts 18:28, Apollos 'mightily convinced the Jews.' Intensity is neutral — it can serve truth or falsehood. The gospel demands passionate proclamation, not tepid agreement.