| bang up | | | |
| banker's dozen | | | |
| bankers' hours | | | |
| bank night | | | |
| bankrupt cart | | | |
| banner year | | | |
| banyan day | | | |
| barber's sign | | | |
| bare-bones | | | |
| bare one's soul | | | |
| bare one's teeth | | | |
| bare poles | | | |
| barhop | | | |
| bark up the wrong tree | | | |
| barnburner | | | |
| barn find | | | |
| bar none | | | |
| barrel of laughs | | | |
| barrel of monkeys | | | |
| bar sinister | | | |
| bar star | | | |
| basement battler | | | |
| base over apex | | | |
| bash into shape | | | |
| bash someone's face in | | | |
| bash someone's head | | | |
| bash the bishop | | | |
| basket house | | | |
| bask in the sunshine | | | |
| bass-ackwards | | | |
| bastardly gullion | | | |
| bat an eyelid | | | |
| bat a thousand | | | |
| bate an ace | | | |
| bat five hundred | | | |
| bat for the other team | | | |
| bathroom singer | | | |
| bat of an eye | | | |
| bat one's eyes | | | |
| Bat-Signal | | | |
| batten down the hatches | | | |
| bat the breeze | | | |
| bawl one's eyes out | | | |
| bawl out | | | |
| be aces with | | | |
| be a hundred years too early | | | |
| be-all and end-all | | | |
| be a man | | | |
| bean counter | | | |
| bear a hand | | | |
| bear away the bell | | | |
| beard the lion in his den | | | |
| bear fruit | | | |
| bear in mind | | | |
| bear oneself | | | |
| be around | | | |
| bear the brunt | | | |
| bear up | | | |
| bear with | | | |
| beast with two backs | | | |
| beat a dead horse | | | |
| beat a retreat | | | |
| beat around the bush | | | |
| beat as one | | | |
| beat Banaghan | | | |
| beat feet | | | |
| be a thing | | | |
| beat it | | | |
| beat off | | | |
| beat off with a stick | | | |
| beat one's brain | | | |
| beat one's swords into ploughshares | | | |
| beat one's swords into plowshares | | | |
| beats me | | | |
| beat someone round the ears | | | |
| beat someone's arse | | | |
| beat someone's ass | | | |
| beat someone's brains out | | | |
| beat the bishop | | | |
| beat the bushes | | | |
| beat the clock | | | |
| beat the cock | | | |
| beat the crowd | | | |
| beat the daylights out of | | | |
| beat the drum for | | | |
| beat the dust | | | |
| beat the odds | | | |
| beat the pants off | | | |
| be at the plague | | | |
| beat the poop out of | | | |
| beat the shit out of | | | |
| beat the stuffing out of | | | |
| beat to the punch | | | |
| beat with the ugly stick | | | |
| beautiful people | | | |
| beauty queen | | | |
| beauty sleep | | | |
| beaver away | | | |
| become of | | | |
| become one flesh | | | |