Old English fleax "flax plant; cloth made with flax, linen," from Proto-Germanic *flakhsan (source also of Old Frisian flax, Middle Dutch and Dutch vlas, Old Saxon flas, Old High German flahs, German Flachs), probably from Proto-Germanic base *fleh- "to plait," from PIE root *plek- "to plait." But some connect it with PIE *pleik- (see flay) from the notion of "stripping" fiber to prepare it.