The only free and comprehensive online etymological dictionary of the Spanish language
dedo m. (Noun) "finger"
12th cent. From Vulgar Latin dicitus. From Latin digitus 'id.' Of unknown origin.
Indo-European
Romance
Asturian deu, Portuguese dedo, dígito, Galician dedo, Catalan dit, French doigt, Italian dito, Aromanian dzeadzit, Romanian: deget, Sardinian didu

In the 3rd or 4th cent. text Appendix Probi we find the line: digitus non dicitus "[the word for 'finger' is] digitus, not dicitus." The author's spelling correction proves how the word was pronounced by common speakers, and offers a rare glimpse of the evolution of Latin into Romance languages such as Spanish.