effectivelyeffectively

Effectively is effective + -ly. Effective comes from French effectif, from Latin effectīvus ‘productive’, from efficiō ‘to bring about’, from faciō ‘to do’.

1. Proto-Indo-Europeanc. 4500–2500 BCE*dʰeh₁k-¹reconstructed
2. Proto-Indo-Europeanc. 4500–2500 BCE*dʰh₁kyéti¹reconstructed
3. Proto-Italicc. 1500–700 BCE*fakjō¹‘to make’reconstructed
4. Latinc. 75 BCE–200 CEfaciō¹‘to do’
5. Latinc. 75 BCE–200 CEefficiō¹‘to make out or work out’
6. Latinc. 75 BCE–200 CEeffectīvus¹‘productive, effective’
7. Frenchc. 1600–presenteffectif¹‘effective’
8. English1500–presenteffective¹
9. Englishearliest quotation 1946effectively¹

1. ¹ Wiktionary, English effectively
2. Earliest quotation in Wiktionary’s entry: 1946, George Johnston, Skyscrapers in the Mist: “The nightclubs generally provide liquor (at a price), pretty…”.