1bang 
/ˈbæŋ/ verb
bangs; banged; bang·ing /ˈbæŋ/ verb 1 a [+ obj] : to cause or allow (something, such as part of your body) to hit something in a way that makes a loud noise
▪ He accidentally banged his knee against the door. ▪ He banged [=bumped, struck] his head getting out of the car. ▪ She fell and banged her elbow. ▪ She banged her fist on the table. ▪ He banged his empty glass on the counter.
b : to hit (something or someone) in a way that makes a loud noise [+ obj] ▪ His knee accidentally banged the door. ▪ The chair fell over and banged the wall. [no obj] — usually + into or against ▪ His knee accidentally banged into the door. ▪ I thought the door was open and banged [=bumped] right into it. ▪ The bird banged into/against the window. ▪ One of the other players banged into her, knocking her to the ground. 2 : to use your hand or a tool to beat or hit (something) in a way that makes a loud noise [+ obj] ▪ He banged the drum. ▪ She banged the table with her fist. [no obj] — + on ▪ He banged on the drum. ▪ She banged on the table. ▪ Who is banging [=pounding] on the door? — see also bang the drum for at 1drum 3 [no obj] : to make a sudden loud noise
▪ I could hear the screen door bang [=slam] as he left. ▪ The window suddenly banged shut. ▪ The pipes banged as the heat came on. 4 [+ obj] informal + offensive : to have sex with (someone)
▪ He accidentally banged his knee against the door. ▪ He banged [=bumped, struck] his head getting out of the car. ▪ She fell and banged her elbow. ▪ She banged her fist on the table. ▪ He banged his empty glass on the counter.
b : to hit (something or someone) in a way that makes a loud noise [+ obj] ▪ His knee accidentally banged the door. ▪ The chair fell over and banged the wall. [no obj] — usually + into or against ▪ His knee accidentally banged into the door. ▪ I thought the door was open and banged [=bumped] right into it. ▪ The bird banged into/against the window. ▪ One of the other players banged into her, knocking her to the ground.
▪ I could hear the screen door bang [=slam] as he left. ▪ The window suddenly banged shut. ▪ The pipes banged as the heat came on.
bang away
[phrasal verb] US, informal : to work hard at something
▪ We have to keep banging away if we want to finish on time. — often + at ▪ The students are banging away at their homework.
▪ We have to keep banging away if we want to finish on time. — often + at ▪ The students are banging away at their homework.
bang heads together
informal : to use angry or forceful methods to control or punish people
▪ I am going to go in there and bang their heads together if they don't start behaving.
▪ I am going to go in there and bang their heads together if they don't start behaving.
bang on about [phrasal verb]
bang on about (something) Brit, informal : to talk about (something) repeatedly or for a long time
▪ She's always banging on about [=going on about] the importance of a good diet.
▪ She's always banging on about [=going on about] the importance of a good diet.
bang out [phrasal verb]
bang out (something) or bang (something) out informal 1 : to produce (something) quickly
▪ He banged out the speech in just a few hours. ▪ The two sides are trying to bang out an agreement. 2 : to play (a song, melody, etc.) loudly on a piano
▪ She carelessly banged out a few melodies on the piano.
▪ He banged out the speech in just a few hours. ▪ The two sides are trying to bang out an agreement.
▪ She carelessly banged out a few melodies on the piano.
bang up [phrasal verb] 1 bang up (something or someone) or bang (something or someone) up US, informal : to injure or damage (something or someone)
▪ She banged up [=hurt] her knee. ▪ He banged up the car. ▪ He was pretty badly banged up [=injured] in the accident. 2 bang up (someone) or bang (someone) up Brit slang : to put (someone) in prison
▪ He got banged up [=locked up] for robbery.
▪ She banged up [=hurt] her knee. ▪ He banged up the car. ▪ He was pretty badly banged up [=injured] in the accident.
▪ He got banged up [=locked up] for robbery.
