scrambler

Noun

• electronic equipment that makes speech unintelligible during transmission and restores it at reception

• a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground

• a rapid mover; someone who scrambles
  • their quarterback was a good scrambler
    
  • scramblers can often unnerve a better tennis player
    

Related words

• Synonyms: 
  trail bike , dirt bike