Definition of phlegm for English Language Learners. : 1  a thick, yellowish liquid that is produced in the nose and throat especially when a person has a cold. : 2  calmness in a difficult or unpleasant situation.
Kneecap (Patellar) Subluxation. A subluxing patella (kneecap) is a temporary, partial dislocation of the kneecap from its normal position in the groove in the end of the thigh bone (femur). This groove is located between two bumps at the end of the thigh bone called the femoral condyles.
A patellar subluxation feels like the kneecap is shifting or jamming out of place. Usually, a subluxated patella returns to its normal position by itself. But repeated incidents can damage the cartilage on the back of the patella or stretch the connective ligaments.