This isn't an idiom that I know about. If you die quietly, you just die without a lot of drama or noise.
No, an idiom is something that makes no sense unless you know the definition. This would be a nonsense phrase because there's on meaning that I've ever heard for it.
"To be" is not an idiom - it's a verb.
No, "haven eaten five bags of crisps" is not an idiom. An idiom is a phrase or expression whose meaning is not easily deduced from the individual words, like "kick the bucket" meaning to die. The phrase you mentioned is a literal statement about consuming crisps and does not convey a figurative meaning.
Pest is not an idiom. It's a word.
Qui-Et-Ly=Quietly. So, meaning that there are three syllables in the word quietly.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
There is no literal idiom -- an idiom is a phrase that seems to mean one thing but actually means something else. The word "literal" means to take the words exactly as they seem to be.An idiom is a phrase particular to a language that is accepted for its figurative meaning, as in "That amazing shot blew me away." Everyone understands that this person means he was amazed. A literal idiom would be the usually humorous thing that happens when you take the idiom for its word for word, not accepted, meaning. That would mean that somehow the amazing shot actually created the air mass necessary to blow this guy away.
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.