If a gun kicks, it jumps back suddenly and with force when the gun is fired.

 to hit (someone or something) with the foot, or to move the feet and legs suddenly and violently
 I kicked the ball as hard as I could. [T]
 He was accused of kicking a man in the face. [T]
 He kicked her up the backside when she wasn't looking. [T]
 Astley kicked his fourth goal in the final minute. [T]
 She felt the baby kicking inside her. [I]
 I sat in a comfortable armchair and kicked off my shoes (=removed them by shaking my
 feet).
 At the age of fifteen she was kicked out of school (=forced to leave by the people in
 charge).
 

 (American) If you kick about something you complain about it.
 I wouldn't kick about the size of your pay raise if I were you.

 (British informal) If you kick against something you refuse to accept it and react strongly against
 it.
 As a boy he always kicked against his father's authority.

 (informal) If you kick an idea around you talk about it generally in a group.
 When they realized it was locked, the youths just kicked the door in/down (=opened it
 by kicking it very hard).

 When a game of football kicks off it begins, with one player kicking the ball.
 FIGURATIVE The new TV series kicks off (=begins) with an investigation into private
 healthcare. See also kickoff.

 There's no point in kicking against the pricks (=complaining about things that you
 cannot change).

 AMERICAN SLANG When the sergeant finds out what you guys have been doing, he's really
 going to kick (some) ass (=punish the people who have done wrong).

 (slang) To kick the bucket/Am kick off is to die.
 When did old Albert kick the bucket then?

 If you kick a/the habit you give up something that you have done for a long time.
 She used to be a heavy smoker but she kicked the habit last year.

 (British) If you are kicking your heels you are forced to wait for something and have nothing to
 do while you wait.

 (American and Australian) If you kick up your heels you have an enjoyable time or are
 suddenly very pleased.
 We really like to kick up our heels when friends come to visit, take them to dinner and a
 show and so on.

 BRITISH Our plans to buy a new car have had to be kicked into touch (=moved to a later
 time).

 (dated) If someone kicks over the traces they behave badly and show no respect for authority.
 It was no wonder that soldiers who risked death every day tended to kick over the
 traces on their evenings off.

 (informal) If someone kicks up a fuss/row they show great annoyance about something, esp.
 when this does not seem necessary.
 He kicked up a tremendous fuss about not being given the best table at the restaurant.

 If you say that someone has been kicked upstairs you mean that they have been moved to a job
 which although it seems better than the one they had, in fact has less power.
 In Britain, experienced politicians are often given a peerage and kicked upstairs to the
 House of Lords.

 If you say you are kicking yourself, you mean that you are very annoyed because you have done
 something stupid or missed a chance.
 They must be kicking themselves for having sold their shares too early.
 When I realized what I had done I could have kicked myself.

 To kick-start a motorcycle is to make its engine start by pressing with your foot a metal bar
 connected to the engine.
 FIG. The Marshall Plan helped to kick-start western Europe's economic recovery (=to
 make it start working again). [T]

 kick  noun [C]
 A kick is the action of kicking something.
 She aimed a kick at the cat when no-one was looking.
 The match was won on penalty kicks.

 If you say that an alcoholic drink has a kick you mean that it is very strong when you were not
 expecting it to be.
 Watch out for the fruit punch, it's got a real kick.

 She was dismissed from her job, which was a (real) kick in the teeth (=a great and
 unexpected disappointment) for her after all the work she'd done.

 (informal) If you say that someone needs a kick up/in the arse/backside/pants you think that
 they are behaving in a silly way and they should be told forcefully to improve their behaviour.
 He hasn't got any real problems, he just needs a good kick up the backside.