Where does “несерьёзный” come from?

несерьёзный (Russian) comes from Russian серьёзный, from French sérieux, from Latin sēriōsus, 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.

несерьёзный (Russian): not serious, light-headed, frivolous; unfounded;...

Definitions

  1. not serious, light-headed, frivolous; unfounded;...

Ancestry of “несерьёзный”, step by step

StepLanguageWordMeaning
1Russianсерьёзныйserious, earnest; serious, grave, important;...
2Frenchsérieuxserious; ?; really? for real?
3Latinsēriōsusserious
4Latinsēriusgrave; earnest; serious
5Latinsēruslate, too late
6Proto-Italicswerjos
7Proto-Indo-Europeanswer-yo-s
8Proto-Indo-Europeanswer-to ache; to fester; wound; injury
Every word from Proto-Indo-European swer-Every word from Proto-Indo-European swer-yo-sEvery word from Proto-Italic swerjos