knee cap
Longman Dictionary of Contemporary English 5++LDOCE 5++ˈknee cap noun [countable] 
HBHthe bone at the front of your knee 髌骨，膝盖骨 →5 see picture at 见图 skeleton
HBHthe bone at the front of your knee 髌骨，膝盖骨 →5 see picture at 见图 skeletonExamples from the Corpus
knee cap• Indiana was without Patterson, its leading scorer and rebounder, because of a slight dislocation of his left knee cap.• Jokes about the subject suggest the punch-line might be followed by the odd shattered knee cap.ˈknee cap nounChineseSyllable
Corpus your the of front bone at the
knee cap
ˈknee cap
noun [countable]
the bone at the front of your knee
ˈknee cap
noun [countable]the bone at the front of your knee