Where does “brat” come from?

brat (Middle Welsh) comes from Proto-Brythonic brad, from Proto-Celtic mratom, from Proto-Indo-European merh₂- — to seize, grip; to pack.

Ancestry of “brat”, step by step

StepLanguageWordMeaning
1Proto-Brythonicbraddeceit, treachery
2Proto-Celticmratomdeceit, betrayal, treachery
3Proto-Indo-Europeanmerh₂-to seize, grip; to pack

Words derived from “brat”

Every word from Proto-Indo-European merh₂- →Every word from Proto-Celtic mratom →Every word from Proto-Brythonic brad →
brat — Etymology, Origin & Word History | Etymology Explorer