[fu.see] n [F fusee, lit., spindleful of yarn, fr. OF, fr. fus spindle, fr. L fusus] (1622) 1: a conical spirally grooved pulley in a timepiece from which a cord or chain unwinds onto a barrel containing the spring and which by its increasing diameter compensates for the lessening power of the spring
2: a red signal flare used esp. for protecting stalled trains and trucks