(uncountable) A twisted strand of fibre used for knitting or weaving.
(nautical) Bundles of fibres twisted together, and which in turn are twisted in bundles to form strands, which in their turn are twisted or plaited to form rope.
(countable) A story, a tale, especially one that is incredible.
Spin a yarn
verb
(intransitive) To tell a story or stories, especially one that is lengthy or unlikely to be true.
1935, Christopher Isherwood, Mr Norris Changes Trains (U.S. title: The Last of Mr Norris), Chapter Thirteen, in The Berlin Stories, New York: New Directions, 1963, p. 152,
“Well, well!” exclaimed Mr. van Hoorn. “Here are the boys! As hungry as hunters, I’ll be bound! And we two old fogies have been wasting the whole afternoon yarning away indoors. My goodness, is it as late as that? I say, I want my tea!”