something that you say when you have finished doing something that you were told to do.

Mission accomplished. I've got everything you asked for on the list.

• a bit of skirt
• a bit on the side
• a bitter pill
• a bitter pill to swallow
• a bit too much
• a black day
• a black mark
• a blank cheque
• a blast from the past
• a bleeding heart
• a blessing in disguise
• a blind alley
• a blind date
• a blind spot
• a blood brother
• a blot on the landscape
• a blow job
• a blue-eyed boy
• a bodice-ripper
• a body blow
• a bolt from the blue
• a bone of contention
• a bone to pick with
• a bone to pick with someone
• a bon mot