1. (n.) One who, or that which, hums; one who applauds by humming.

2. (n.) A humming bird.

Amtrak Jehu acrobat aerialist aeronaut aeroplaner aeroplanist agiotage air pilot airman airplanist arbitrage astronaut aviator baggage train bareback rider barnstormer birdman buying in cable railroad calculated risk captain chance choo-choo circus artist cloud seeder clown cog railroad cog railway commercial pilot copilot crop-duster el electric electric train elevated equestrian director equilibrist equity capital express express train flutter fortune freight freight train freighter funicular gamble goer goods train hazard hell-driver high-wire artist horse racer hummer hustler instructor interurban jet jockey jockey juggler licensed pilot lightning express limited lion tamer liquidation local luck metro milk train monorail parliamentary parliamentary train passenger train pilot play plunge profit taking racer rack-and-pinion railroad railroad train rainmaker rattler ringmaster risk rolling stock round trade runner scalping scorcher shuttle shuttle train sizzler slack-rope artist snake charmer special speculation speed demon speeder spot sale stepper stockjobbery stockjobbing streamliner stunt flier stunt man subway sword swallower test pilot tightrope walker train trapeze artist tube tumbler turfman turn uncertainty underground venture venture capital way train wingman