Where does “serieux” come from?

serieux (Old French) comes from Medieval Latin seriosus, from Latin sērius, from Latin sērus, from Proto-Italic swerjos, from Proto-Indo-European swer-yo-s, from Proto-Indo-European swer- — to ache; to fester; wound; injury.

Ancestry of “serieux”, step by step

StepLanguageWordMeaning
1Medieval Latinseriosusserious
2Latinsēriusgrave; earnest; serious
3Latinsēruslate, too late
4Proto-Italicswerjos
5Proto-Indo-Europeanswer-yo-s
6Proto-Indo-Europeanswer-to ache; to fester; wound; injury

Words derived from “serieux

Every word from Proto-Indo-European swer-Every word from Proto-Indo-European swer-yo-sEvery word from Proto-Italic swerjos