thread, esp a spun thread, e.g. of wool, cotton, or hemp, as prepared and used for weaving, knitting, sewing, and rope-making
informal a narrative of adventures, esp a tall tale
And all I ask is a merry yarn from a laughing fellow-rover — John Masefield
Aus, NZ, informal a conversation or chat
[Old English gearn; (sense 2) from the phrase to spin a yarn to tell a long story]