fus·ty \ˈfəstē, -ti\adjective (-er/-est) Etymology: Middle English, from fust wine cask (from Middle French, club, stick, tree, cask, from Latin fustis club, staff) + -y — more at beat 1.Britain: impaired by age or dampness : moldy < fusty hay > 2.: saturated with dust and stale odors : musty < rummage into fusty rooms — Howard Griffin > 3.: old-fashioned or rigidly conservative : antiquated < a fusty elderly gentleman in a threadbare morning coat — George Bellairs >