“Felicitate” is based on the Latin “felicitatus,” meaning “to make happy,” from the Latin “fēlīx” (“happy”). “Felicitate” can be a straightforward synonym for “to congratulate,” though the term is more nuanced than that. Looking at the Latin root “felicitatus,” meaning “to make happy,” a person who felicitates is celebrating another’s happiness, or wishing joy upon that person. By offering felicitations (the noun form), there is no jealousy or sarcasm, but only pure happiness in the congratulations.