effectiveeffective

Effective comes from French effectif, from Latin effectīvus ‘productive, effective’, from efficiō ‘to bring about’; equivalent to effect + -ive.

1. Latinc. 75 BCE–200 CEefficiō¹‘to make; bring about’
2. Latinc. 75 BCE–200 CEeffectīvus¹‘productive; effective’
3. Frenchc. 1600–presenteffectif¹‘effective’
4. Englishearliest quotation 1651effective¹

1. ¹ Wiktionary, English effective
2. Earliest quotation in Wiktionary’s entry: 1651, Jeremy Taylor, The Rule and Exercises of Holy Living. […]: “Whosoever is an effective, real cause of doing his…”.