It means an action or statement that causes surprise and usually a bit of doubt or disbelief among those who hear it. "His announcement that he had invented a gadget that would allow any car to get 80 miles to the gallon caused some raised eyebrows in automotive circles."
It means to create a huge fuss over, or to make a big deal about.
One of my eyebrows is always raised because it is a natural expression that I have, which may convey curiosity, skepticism, or surprise.
"To be" is not an idiom - it's a verb.
Raised Eyebrows
Pest is not an idiom. It's a word.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
The professor raised his eyebrows, showing how doubtfully he was receiving my explanation.
The idiom means impress someone is egg on
It's not an idiom - to cope means to deal with, or to handle
"Old hand" is an idiom meaning having lots of experience.
It is not an idiom. It is an expression. The difference is that an idiom's meaning cannot be derived from the meaning of its individual words. In the expression wolfing down food, the meaning is clearly derived from the meaning of the words, and people have been saying it for hundreds of years.