thrall

From Middle English thral, thralle, threl, threlle, from Old English þrǣl (“thrall, slave, servant”), from Old Norse þræll (“slave”), from Proto-Germanic *þrahilaz, *þragilaz, *þrigilaz (“runner, gofer, servant”), from Proto-Indo-European *tregʰ- (“to pull, drag, race, run”), possibly a variant of *dʰregʰ- (“to run”); related to Gothic 𐌸𐍂𐌰𐌲𐌾𐌰𐌽 (þragjan), Old English þrǣġan (“to run”).

From Middle English thrallen, from the noun above. Compare Old Norse þræla.