a babe in arms
a babe in the woods	a bad taste in my mouth
a bad time	a ball-park figure
a bare-faced lie	a barnburner
a barrel of laughs	a basket case
a bawling out	a bed of roses
a bee in her bonnet	a beehive of activity
a big rig	a big shot
a big wheel	a big wig
a bird in the hand is worth two in the bush	a bit at sea
a bit dense	a bit off/a bit mental
a bite to eat	a bitter pill
a black mark	a blackout (TV)
a blackout (war)	a blank look
a blast	a blessing in disguise
a blowout	a blowout
a bone to pick	a breath of fresh air
a breath of wind	a brick
a brick short	a brick short
a budding genius	a budding genius
a bull in a China shop	a bull in a China shop
a bun in the oven	a bun in the oven
a bunch of malarkey	a bunch of malarkey
a bundle of nerves	a bundle of nerves
a card	a card
a case of	a case of
a caution	a checkup
a chicken in every pot	a chin wag
a chip off the old block	a chunk of change
a clean bill of health	a cliff-hanger
a close call	a close shave
a clutch hitter (baseball)	a common thread
a contract out on	a coon's age
a crash course	a crush on
a crying shame	a cut above
a cut-up	a daredevil
a dead giveaway	a dead heat
a dead loss	a dead ringer
a different kettle of fish	a dime a dozen
a doggy bag	a dog's age
a dog's breakfast	a dog's life
a double-edged sword	a downer (sadness)
a drag	a dressing down
a drop in the bucket	a duke's mixture
a dust-up	a fair shake
a falling out	a false move
a far cry	a faraway look
a fat lip	a feather in your cap
a fifth wheel	a fighting chance
a fill-up	a fine line
a fine-toothed comb	a firm hand
a flash in the pan	a fleeting glance
a fly on the wall	a fool and his money are soon parted
a foregone conclusion	a free hand
a free-for-all	a freeze on
a fresh pair of eyes	a fresh start
a full house (cards)	a full plate
a gaggle of geese	a game one
a ghost of a chance	a go
a go-getter	a going concern,
a golden opportunity	a goner
a good arm	a good egg
a good head	a good sport
a grain of salt	a grain of truth
a grandfather clause	a handful
a handout	a hard day
a hard row to hoe	a hard time
a hassle	a head start
a heavy day	a heavy hitter
a heavyweight	a helping hand
a hill of beans	a hit
a holy pile	a hoot
a horse of a different color	a hot hand
a hot ticket	a hotdog
a hothead	a hotshot
a household name	a howling blizzard
a humdinger	a jim dandy
a keeper	a leg up
a level playing field	a lick and a promise
a lift	a little birdy told me
a little off	a little off
a little steep	a little thick
a long shot	a loose cannon
a losing streak	a lost cause
a lot of bunk	a lot of falderal
a lot on the ball	a lucky break
a lucky streak	a major
a man of few words	a man of the cloth
a marked man	a mental block
a month of Sundays