kneecaps

/N IY1 K AE0 P S/
noun
  1. 1

    The flat, roundish bone in the knee.

  2. 2

    (roofing) A metal cover trim that fits over a panel rib after it has been cut and bent.

  3. 3

    A cap or strong covering for the knees, used chiefly for horses, to protect their knees in case of a fall.

Source: https://en.wiktionary.org/wiki/kneecap, https://en.wiktionary.org/wiki/kneecaps