|back away||Move backwards, in fear or dislike||When he saw the dog, he backed away.|
|back down||Withdraw; concede defeat.||Local authorities backed down on their plans to demolish the cinema.|
|back up||1) Give support or encouragement|
2) make a copy of (file, program…)
|1) If I tell the boss we’ve got too much work, will you back me up?|
2) It is recommended to back up all files.
|bail out||1) Pay money to secure someone’s release|
2) Rescue from financial difficulties
|1) When he was arrested, his family refused to bail him out.|
2) The government bailed out the bank.
|bank on||Base your hopes on something/someone.||Don’t forget the date. I’m banking on your help.|
|beef up||Improve or make more substantial||He beefed up his presentation with diagrams and statistics.|
|black out||Faint; lose consciousness||When he fell off the horse, he blacked out.|
|block off||Separate using a barrier.||The area was blocked off during the demonstration.|
|blow up||1) Explode.|
2) Be destroyed by an explosion.
|1) The terrorists said the bomb wouldblow up at 9 o’clock.|
2) The car blew up but luckily there was nobody in it.
|boil down to||Be summarized as||The problem boils down to a lack of money.|
|boot up ||Start a computer by loading an operating system or program.||Just give me a few minutes to boot up the computer.|
|break away||Escape from captivity.||A few horses broke away from the paddock.|
|break down||1) Go out of order, cease to function.|
2) Lose control of one’s emotions.
|1) John’s car broke down on the way to the airport.|
2) The parents broke down when they heard the bad news.
|break into||Enter by force.||The burglars broke into the house around midnight.|
|break off||1) Stop, discontinue|
2) Stop speaking
|1) It was decided to break off diplomatic relations with that country.|
2) She broke off in the middle of a sentence.
|break out||Start suddenly.||Riioting broke out as a result of the strike.|
|break out of||Escape from a place by force.||Three prisoners broke out of jail.|
|break up||Come to an end (marriage, relationship…)||After her marriage broke up, Emma went to live in London.|
|bring up||Raise (a child).||She stopped working in order to bring upher children.|
|brush up on||Improve, refresh one’s knowledge of something.||Mary decided to brush up on her Spanish before going to South-America.|
|bump into||Meet by accident or unexpectedly.||Pedro bumped into his English teacher at the supermarket.|
|burn out||1) Stop (something) working|
2) Become exhausted from overworking
|1) The fuse has burnt out.|
2) Tom will burn himself out if he doesn’t slow down.
|butt in (on)||Interrupt impolitely.||It’s rude to butt in on a conversation.|