To rest upon the haunches, or the lower extremity of the trunk of the body; said of human beings, and sometimes of other animals; as, to sit on a sofa, on a chair, or on the ground
To remain in a state of repose; to rest; to abide; to rest in any position or condition
If you are sitting somewhere, for example in a chair, your bottom is resting on the chair and the upper part of your body is upright. Mother was sitting in her chair in the kitchen They sat there in shock and disbelief They had been sitting watching television He was unable to sit still for longer than a few minutes