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.
Another form of mal-tracking, associated with a tendency to recurrent patella subluxation is when the kneecap shifts outwards (laterally) as the knee straightens and has to shift inwards (medially) to re-enter the trochlea groove as the knee starts to bend again.