to start working very hard, or to start doing something in an excited way.

With her exams only two weeks away, she's gone into overdrive and is studying ten hours a day.

The tabloid press went into overdrive at the news that the princess was getting married again.

• bore the socks off
• bore to death
• bore to tears
• born and bred
• born to
• born to be
• born to be something
• born to do something
• born with a silver spoon in mouth
• born with a silver spoon in your mouth
• boss around
• boss someone around
• bossy boots
• bottle up
• bottle up something
• bottom drawer
• bottom drops out of the market
• bottom falls out of the market
• bottom fell out
• bottom fell out of
• bottom fell out of something
• bottomless pit
• bottom line
• bottom of the barrel
• bottom of the heap