1
general::
Phrase(s): spin a yarn
Fig. to tell a tale. • Grandpa spun an unbelievable yarn for us. • My uncle is always spinning yarns about his childhood.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Tell a story, especially a long drawn-out or totally fanciful one, as in This author really knows how to spin a yarn, or Whenever he's late he spins some yarn about a crisis. Originally a nautical term dating from about 1800, this expression probably owes its life to the fact that it embodies a double meaning, yarn signifying both "spun fiber" and "a tale."
American Heritage Idioms