In wrestling, a lariat is when an attacking wrestler runs towards an opponent, wraps his arm around their upper chest and neck and then forces them to the ground. This move is similar to a clothesline, the difference being that in a clothesline the wrestler's arm is kept straight to the side of the wrestler during the move, while in the lariat the wrestler strikes their opponent with his arm.
There are multiple variants of lariat:
1) Northern Lariat or Enzui Lariat: A lariat to the back of the opponent's neck and shoulders. Used by Total Nonstop Action Wrestling alumnus and current WWE superstar Robert Roode.
2) Burning Lariat or Short Range Lariat: A lariat where the wrestler doesn't run but simply strikes the opponent while standing next to him. The wrestler can also hold the opponent's head up before performing the lariat with his other arm. The Burning Lariat is a common variant among Japanese wrestlers, with retired Japanese wrestler Kobashi Kenta among of the users of this variation.
3) Short-arm Lariat: A variation where the wrestler grabs one of the opponent's wrists with his hand and pulls the opponent closer, striking him with the lariat with his other arm. New Japan Pro Wrestling wrestler Okada Kazuchika's Rainmaker finishing move is a variation of this, where he holds his opponent in a ripcord position then spins him out to hit the short-arm lariat.
4) Discus Lariat: The wrestler spins in place before he hits the lariat. Used by the late All Elite Wrestling wrestler/WWE alumnus Mr. Brodie Lee (a.k.a. Luke Harper)
Typically, a lariat is used as a finishing move while the clothesline is simply a basic strike attack. The main difference aside from the mechanics of the movement is the stiffness. Lariats are essentially a very stiff clothesline used as a finisher rather than a basic strike.