Felixempra was a charm that presumably aided in granting good fortune to the caster; it was used as the potion-making spell for Felix Felicis. Given how Felix Felicis was invented by Zygmunt Budge, it is possible that this spell was thus also created by him.
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".
Behind the scenes
- Pottermore revealed that the effects of Felix Felicis cannot be duplicated by a spell. This indicates that Felixempra can only be used to enchant the potion, but cannot independently be used on a person.
- Wonderbook: Book of Potions (First appearance)