hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella
"The surgeon carefully examined the knee, noting how the patella sat securely in front of the hinge joint that connects the thigh bone to the shin bones."
the part of a trouser leg that provides the cloth covering for the knee
"The tailor carefully cut the extra fabric into a patch to reinforce the knee area on the backside of his trousers."
In humans, the joint or the region of the joint in the middle part of the leg between the thigh and the shank.
"She carefully applied a bandage to her knee after falling off her bike."
In plain English: The knee is the joint on your leg that connects your thigh to your shin and lets you bend it backward.
"She fell down and hurt her knee while playing soccer in the park."
Usage: Use "knee" to refer specifically to the joint connecting your upper and lower legs rather than using it as a general term for any body bend. You can also use this word metonymically when discussing injuries or actions involving that specific area, such as kneeling on one's knee.
To kneel to.
"The warrior kneeled before his king as a sign of submission."
The word "knee" comes from Old English and originally meant the joint connecting the upper and lower leg. Its roots trace back to ancient Indo-European languages where it referred to this same body part.