kneepads

/ˈniːpædz/
noun
  1. Padded coverings worn over the knees to protect them during activities such as sports, work, or gardening.
    • Gardeners often use kneepads to avoid sore knees while weeding.
    • He put on his kneepads before starting to lay the new floor tiles.
    • The volleyball players wore kneepads to protect themselves when diving for the ball.