witches’ knickers
 n.pl.— «Alaskans call them “tundra ghosts” and “landfill snowbirds.” In China, they’re “white pollution.” South Africans have sarcastically dubbed them their “national flower.” Snagged in treetops in Ireland, they become “witches’ knickers.”» —“Blight of bags bringing bans” by Margie Wylie Times-Picayune (New Orleans, La.) Oct. 21, 2004. (source: Double-Tongued Dictionary)