Weird can also mean prone to strange or unpredictable behavior. Both whimsical and capricious are derived from an earlier English word whim-wham which is of unknown origin. Whim-wham had much the same meaning as caprice, but could also refer to a strange object or garment. Music theme by Joshua Stamper 2006©New Jerusalem Music/ASCAP Bizarre means full or characterized by whims, which are strange ideas that usually come to mind very suddenly. If you decide to fly to Europe at the last minute, you could say you went there on a whim.