Bone on Top of a Leg Joint; Babies Don't Have One
This page is the CodyCross answer for the clue below from Physics, Group 1888, Puzzle 3 (Magnetic Field).
Question is: Bone on Top of a Leg Joint; Babies Don't Have One
and the answer is: KNEECAP
Word Meaning:
KNEECAP — (anatomy) The flat, roundish bone in the knee.
Definitions from Wiktionary.