get (your) brain in gear

informal

to make yourself start thinking clearly and effectively.

I've got to get my brain in gear for the meeting this afternoon.

• poacher turned gamekeeper
• poetic justice
• poetic license
• po-faced
• point-blank
• point blank
• point of no return
• a babe in the woods
• a baby boomer
• a back-handed compliment
• a backroom boy
• a backseat driver
• a bad apple
• a bad egg
• a bad workman blames his tools.
• a bag lady
• a bag of bones
• a baker's dozen
• a balancing act
• a ball and chain
• a ball-breaker
• a ballpark estimate
• a ballpark figure
• a balls-up
• a banana republic