| A | B |
| baker's dozen | 13 of anything for the price of 12 |
| backseat driver | a bossy person who gives unwanted advice or directions |
| bark is worse than your bite | the way a person sounds is much worse than their actions |
| barking up the wrong tree | to have the wrong idea about something |
| back to square one | return to the beginning because of a failure to meet the goal |
| beauty is in the eye of the beholder | different people have different opinions |
| beat around the bush | to avoid answering a question |
| beat a dead horse | to keep fighting a losing battle |
| batten down the hatches | prepare for an emergency |
| blow your own horn | to brag about yourself |