bats-in-the-belfry

bats-in-the-belfry

n (functioning as singular)
(Plants) a hairy Eurasian campanulaceous plant, Campanula trachelium, with bell-shaped blue-purple flowers
adj
slang mad; demented
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014