A varus deformity is an excessive inward angulation (medial angulation, that is, towards the body's midline) of the distal segment of a bone or joint.

The terms varus and valgus always refer to the direction that the distal segment of the joint points.

For example, in a valgus deformity of the knee, the distal part of the leg below the knee is deviated outward, in relation to the femur, resulting in a knock-kneed appearance.

Conversely, a varus deformity at the knee results in a bowlegged with the distal part of the leg deviated inward, in relation to the femur.

The terminology is made confusing by the etymology of these words.