Real Dictionary

sit
verb: 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.
verb: If you sit someone somewhere, you tell them to sit there or put them in a sitting position.
verb: When you sit somewhere, you lower your body until you are sitting on something.

sit in American English
to rest the weight of the body upon the buttocks and the back of the thighs, as on a chair; be seated

sit in American English 1
intransitive verb: to rest with the body supported by the buttocks or thighs; be seated
transitive verb: to cause to sit; seat

sit in American English 2
verb: may it be

sit in British English
abbreviation for: stay in touch
verb: to adopt or rest in a posture in which the body is supported on the buttocks and thighs and the torso is more or less upright