New England. a wooded, uninhabited area.
They couldn't believe anyone could just walk out of the willowwacks, Navy SEAL or not. Aaron Gwyn, Wynne's War, 2014
There aren't many airports in eastern Canada; you look at one like Upper Blackville, out there in the spruce-and-fir willowwacks, and wonder what it's doing there. The AOPA Pilot: Voice of General Aviation, Volume 37, 1994
Willowwacks is of uncertain origin.
(Source: dictionary.com Word of the Day, Jan. 12, 2017)