Definition of fleetness in US English:

fleetness

noun

literary
  • See fleet

    • ‘When I ran, I looked ungainly in my mind's eye, which could see all too well the fleetness of other children.’
    • ‘If Jane is a better runner than Sally, there is nothing wrong about rewarding Jane for fleetness of foot.’
    • ‘Their combination and their fleetness of action was impressive.’
    • ‘That leaves you plenty of time to apply your freshly honed agility and fleetness to any adventurous pursuit.’
    • ‘He was noted at school for his fleetness of foot and it was said that he could outrun any of those fleet and nimble flock.’