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.
Dislocation of the patella occurs when the patella moves or is moved to the outside of this groove and onto the bony head of the femur (lateral femoral condyle). The patella may also sublux rather than fully dislocate, meaning it moves partially out of position.