Felixempra was the incantation of a charm used to complete the brewing process of Felix Felicis. As the effects of Felix Felicis could not be replicated with spells, this was the spell's only effect. Subsequently, this spell was likely created by Zygmunt Budge, as he invented the potion.
Felixempra shares its etymology with the potion it is used on, Felix Felicis - Felix in Latin means "happy" or "fortunate". Felixempra also seems to be combination or portmanteau of felix and sempra, where semper is Latin for "always". Overall, the incantation roughly means, "always fortunate."
- Wonderbook: Book of Potions (First appearance)