Where does “threl” come from?

threl (Middle English) comes from Old English þrǣl, from Old Norse þræll, from Proto-Germanic þragilaz, from Proto-Indo-European trāgʰ- — pull, drag, race, run; to pull, drag, race, run.

Ancestry of “threl”, step by step

StepLanguageWordMeaning
1Old Englishþrǣlthrall, slave, servant
2Old Norseþrællslave
3Proto-Germanicþragilazrunner; gofer; servant
4Proto-Indo-Europeantrāgʰ-pull, drag, race, run; to pull, drag, race, run
Every word from Proto-Indo-European trāgʰ- →Every word from Proto-Germanic þragilaz →Every word from Old Norse þræll →