Definition of "woolpack"

There was a Fellow with a Wen in his Neck, larger than five Woolpacks, and another with a couple of wooden Legs, each about twenty foot high.

1726 October 28, [Jonathan Swift], “The Country Described. […]”, in Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume I, London: […] Benj[amin] Motte, […], part II (A Voyage to Brobdingnag), page 220

During the following hour, the high white fleecy clouds lowered and congested and grayed into woolpack.

2017, Dean Koontz, The Silent Corner, page 10