spin a yarn - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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.”