The initial idioms of the letter B

back-cloth star	backdoor
backdoor man	backdoor trot
backdoor trots	backed
back and fill	back off
backed up	back-ender
backer	backfire on someone
backfire on	backfire
background	backhanded
backhanded compliment	back-handed compliment
backhander	backing and filling
back away	backing
back-of-the-envelope calculation	back-order
backpedal	backroom
backroom boy	back
backseat	backseat driver