1.  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. [1913 Webster]
"And he came and took the book put of the right hand of him that sate upon the seat." [1913 Webster]
"I pray you, jest, sir, as you sit at dinner." [1913 Webster]

2.  To perch; to rest with the feet drawn up, as birds do on a branch, pole, etc. [1913 Webster]

3.  To remain in a state of repose; to rest; to abide; to rest in any position or condition. [1913 Webster]
"And Moses said to . . . the children of Reuben, Shall your brothren go to war, and shall ye sit here?" [1913 Webster]
"Like a demigod here sit I in the sky." [1913 Webster]

4.  To lie, rest, or bear; to press or weigh; -- with on; as, a weight or burden sits lightly upon him. [1913 Webster]
"The calamity sits heavy on us." [1913 Webster]

5.  To be adjusted; to fit; as, a coat sts well or ill. [1913 Webster]
"This new and gorgeous garment, majesty,
Sits not so easy on me as you think." [1913 Webster]

6.  To suit one well or ill, as an act; to become; to befit; -- used impersonally. Chaucer. [1913 Webster]

7.  To cover and warm eggs for hatching, as a fowl; to brood; to incubate. [1913 Webster]
"As the partridge sitteth on eggs, and hatcheth them not." [1913 Webster]

8.  To have position, as at the point blown from; to hold a relative position; to have direction. [1913 Webster]
"Like a good miller that knows how to grind, which way soever the wind sits." [1913 Webster]
"Sits the wind in that quarter?" [1913 Webster]

9.  To occupy a place or seat as a member of an official body; as, to sit in Congress. [1913 Webster]

10.  To hold a session; to be in session for official business; -- said of legislative assemblies, courts, etc.; as, the court sits in January; the aldermen sit to-night. [1913 Webster]

11.  To take a position for the purpose of having some artistic representation of one's self made, as a picture or a bust; as, to sit to a painter. [1913 Webster]

1.  To sit upon; to keep one's seat upon; as, he sits a horse well. [1913 Webster]
"Hardly the muse can sit the headstrong horse." [1913 Webster]

2.  To cause to be seated or in a sitting posture; to furnish a seat to; -- used reflexively. [1913 Webster]
"They sat them down to weep." [1913 Webster]
"Sit you down, father; rest you." [1913 Webster]

3.  To suit (well or ill); to become. [1913 Webster]

sit, v. & n.
--v. (sitting; past and past part. sat)
1 intr. adopt or be in a position in which the body is supported more or less upright by the buttocks resting on the ground or a raised seat etc., with the thighs usu. horizontal.
2 tr. cause to sit; place in a sitting position.
3 intr. a (of a bird) perch. b (of an animal) rest with the hind legs bent and the body close to the ground.
4 intr. (of a bird) remain on its nest to hatch its eggs.
5 intr. a be engaged in an occupation in which the sitting position is usual. b (of a committee, legislative body, etc.) be engaged in business. c (of an individual) be entitled to hold some office or position (sat as a magistrate).
6 intr. (usu. foll. by for) pose in a sitting position (for a portrait).
7 intr. (foll. by for) be a Member of Parliament for (a constituency).
8 tr. & (foll. by for) intr. Brit. be a candidate for (an examination).
9 intr. be in a more or less permanent position or condition (esp. of inactivity or being out of use or out of place).
10 intr. (of clothes etc.) fit or hang in a certain way.
11 tr. keep or have one's seat on (a horse etc.).
12 intr. act as a babysitter.
13 intr. (often foll. by before) (of an army) take a position outside a city etc. to besiege it.
--n. the way a dress etc. sits on a person.

Idiom:
be sitting pretty be comfortably or advantageously placed. make a person sit up colloq. surprise or interest a person. sit at a person's feet be a person's pupil. sit at home be inactive. sit back relax one's efforts. sit by look on without interfering. sit down
1 sit after standing.
2 cause to sit.
3 (foll. by under) submit tamely to (an insult etc.). sit-down adj. (of a meal) eaten sitting at a table. sit-down strike a strike in which workers refuse to leave their place of work. sit heavy on the stomach take a long time to be digested.
sit in
1 occupy a place as a protest.
2 (foll. by for) take the place of.
3 (foll. by on) be present as a guest or observer at (a meeting etc.). sit-in n. a protest involving sitting in. sit in judgement assume the right of judging others; be censorious. sit loosely on not be very binding.
sit on
1 be a member of (a committee etc.).
2 hold a session or inquiry concerning.
3 colloq. delay action about (the government has been sitting on the report).
4 colloq. repress or rebuke or snub (felt rather sat on). sit on the fence see FENCE.
sit on one's hands
1 take no action.
2 refuse to applaud. sit out 1 take no part in (a dance etc.).
2 stay till the end of (esp. an ordeal).
3 sit outdoors.
4 outstay (other visitors).
sit tight colloq.
1 remain firmly in one's place.
2 not be shaken off or move away or yield to distractions.
sit up
1 rise from a lying to a sitting position.
2 sit firmly upright.
3 go to bed later than the usual time.
4 colloq. become interested or aroused etc. sit-up n. a physical exercise in which a person sits up without raising the legs from the ground. sit up and take notice colloq. have one's interest aroused, esp. suddenly. sit-upon colloq. the buttocks. sit well have a good seat in riding. sit well on suit or fit.

Etymology:
OE sittan f. Gmc

VB  depress, lower, let down, take down, let down a peg, take down a peg, cast, let drop, let fall, sink, debase, bring low, abase, reduce, detrude, pitch, precipitate, overthrow, overturn, overset, upset, subvert, prostate, level, fell, cast down, take down, throw down, fling down, dash down, pull down, cut down, knock down, hew down, raze, raze to the ground, rase to the ground, trample in the dust, pull about one's ears, sit, sit down, couch, squat, crouch, stoop, bend, bow, courtesy, curtsy, bob, duck, dip, kneel, bend the knee, bow the knee, bend the head, bow the head, cower, recline.

baby sit, sit back, sit by, sit down, sit down strike, sit down with, sit in, sit in on, sit on, sit out, sit tight, sit up