crack a joke = tell a joke or a funny story (Used in very informal settings. )

He was cracking jokes all night long, it was so funny! - Every time you crack a joke nobody laughs.

a blessing in disguise

something that at first appears to be bad or unlucky but is actually good Losing my job was a blessing in disguise - I never would have found this one if it hadn't happened.

a blast from the past

something that makes you suddenly remember an earlier time in your life Here's a blast from the past - the 1960s group the Mamas and the Papas were inducted into the Rock and Roll Hall of Fame this week.

a bitter pill (to swallow)

an unpleasant situation that must be accepted Losing the championship was a bitter pill to swallow for a team that was used to winning every year. Having his fate in the hands of others is a bitter pill for this proud man.

a bite to eat.

a small meal You'll feel better once you've had a bite to eat.

Usage notes: often used with quick: I usually sleep late and just have a quick bite to eat when I get to work.

a bit (too) much

unreasonable or unfair I think it's a bit much to expect anyone to play three tennis matches in one day. Bill went at four in the morning and had to wait four hours to get in, but that was just a bit too much for me.

a bird's eye view

the appearance of something seen from above The large painting offers a bird's eye view that shows the layout of the ancient city.

Usage notes: sometimes used to show how an animal's view is different: A basement window gives you a dog's eye view of the world - all you see is the bottom of the fire hydrant and passing feet on the sidewalk.

a bird in the hand

what you have or know is better than something you do not have or know Investors are focused on the bird in the hand, and not looking for new opportunities very much these days.

Usage notes: based on the full form, a bird in the hand is worth two in the bush, which is rarely used

Etymology: based on the idea that a person should catch one bird that is easy to catch rather than hoping to find more somewhere else

a bad/rotten apple

one bad person in a group of people who are good You'll find the occasional rotten apple in every organization.

a backseat driver

1. a passenger in a car who continuously tells the driver how they should drive Mike's a real backseat driver and I find it so irritating.

2. (mainly American) someone who expects to control things although it is not their responsibility to do this Tell her you're in charge now. It's time she stopped being a backseat driver.

a backroom boy (informal)

someone who does a lot of work in the type of job where they are not often seen by the public (often plural) Editors are very much the backroom boys of the film world

a back-handed compliment (British, American & Australian) also a left-handed compliment (American)

a remark which seems approving but which is also negative He gave me that classic back-handed compliment. He said I played football very well 'for a woman'.

a baby boomer (mainly American)

someone who was born between 1945 and 1965, a period in which a lot of babies were born Clinton was the first baby boomer in the White House. The ads are supposed to appeal to the baby boomer generation.

a babe in the woods (American & Australian)

someone who has not had much experience of life and trusts other people too easily When it comes to dealing with men, she's a babe in the woods

'Tis better to have loved and lost than never to have loved at all

Prov. Love is such an important experience that even the pain of losing someone you love is better than not having loved that person. (A line from Alfred Lord Tennyson's poem, "In Memoriam A. H. H.") Tom: I've been so miserable since Nancy and I broke up. I wish I'd never met her. Fred: Come on, now—'tis better to have loved and lost than never to have loved at all.