1. Monkey business
silly or deceitful behavior; stupid or time-wasting activity
Our accountant has been fired as there was some monkey business with the books.
Are you still fiddling about with those old tools? Stop the monkey business and get some new ones.
2. Rat race
an exhausting routine, a hectic struggle for success
I’m so tired of the rat race. I’d love to retire and move to the country.
She started to work from home as she couldn’t stand the rat race at the office.
3. Cat burglar
a stealthy burglar who climbs into buildings, usually through upper windows, skylights, etc.
Grandfather’s old telescope has disappeared from the loft. It must have been a cat burglar that took it.
The inspector was surprised by the exploits of a cat burglar who only stole from upper floors and attics.
4. Top dog
the most important person in a group, somebody with the dominant position or highest authority
I don’t want to be the top dog at our company, I just do my job as well as I can.
Peter is the top dog at English in our class.
5. Cash cow
a dependable source of income; a product or service that makes money
Our company’s cash cow is the sales department, which makes enough income to finance the developers.
The publisher saw the new bestseller as a cash cow.
6. Eager beaver
an enthusiastic hard worker; someone very excited to start a task
The new secretary is an eager beaver. Although she comes to work at seven every day, she’s the last to leave in the evening.
Don’t be an eager beaver; we have plenty of time to do this job.
7. Road hog
a inconsiderate driver, someone who drives carelessly and selfishly
Sorry that we’re so slow, but there is no way to overtake that road hog in front of us.
A road hog nearly ran me over at the crossing as he failed to stop at the sign.
8. Black sheep
an undesirable member of a group, a disliked person, somebody who causes shame or embarrassment due to deviation
Don’t be surprised that he doesn’t want to take over father’s business, he’s always been the black sheep of the family.
They called me the black sheep as I didn’t want to go to the pub and play billiards with them.