flaxseed (n.)

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.

Middle English sēd, from Old English sēd (Anglian), sæd (West Saxon), "that which may be sown; an individual grain of seed," from Proto-Germanic *sediz "seed" (source also of Old Norse sað, Old Saxon sad, Old Frisian sed, Middle Dutch saet, Old High German sat, German Saat). This is reconstructed to be from PIE *se-ti- "sowing," from root *sē- "to sow."

Figurative sense of "offspring, progeny, posterity," now rare or archaic except in biblical use, was in Old English; the figurative meaning "that from which anything springs, latent beginning" is by late Old English. From late 14c. as "act or time of sowing." The meaning "semen, male fecundating fluid," also now archaic or biblical, is from c. 1300. For the sporting sense (by 1924), see seed (v.).