yarn (n.) Look up yarn at Dictionary.com
Old English gearn "spun fiber, spun wool," from Proto-Germanic *garnan (source also of Old Norse, Old High German, German garn, Middle Dutch gaern, Dutch garen "yarn"), from PIE root *ghere- "intestine, gut, entrail" (source also of Old Norse gorn "gut," Sanskrit hira "vein; entrails," Latin hernia "rupture," Greek khorde "intestine, gut-string," Lithuanian zarna "gut"). The phrase to spin a yarn "to tell a story" is first attested 1812, from a sailors' expression, on notion of telling stories while engaged in sedentary work such as yarn-twisting.