Meaning of “knee” - Learner’s Dictionary

knee

noun [ C ] us uk /niː/
Jamie fell over and scraped his knee.Jogging puts a lot of stress on your knee joints.His leg was amputated at the knee.Bend your knees when lifting heavy objects.Simon hurt his knee playing football.
LEG

B1 the middle part of your leg where it bends:

a knee injury
TROUSERS

the part of a pair of trousers that covers the knee

(Definition of “knee” from the Cambridge Learner’s Dictionary © Cambridge University Press)