Where does “Popescu” come from?

Popescu comes from Romanian -escu, a diminutive suffix from Old Church Slavonic попъ meaning "priest," ultimately derived from Latin -iscus and Proto-Indo-European -iskos.

Ancestry of “Popescu”, step by step

StepLanguageWordMeaning
1RomanianPopescu—
2Romanian-escusuffix forming many Romanian surnames, e.g....
3Romanian-esc-esque, -ish; Used with a stem to form the...
4Latin-ēscōAttaches to a stem (a noun or adjective) to form a verb meaning “to become [stem]” or similar
5Proto-Italic*-ēskō—
Every word from Proto-Italic *-ēskō →Every word from Romanian -escu →Every word from Latin -ēscō →