meaning of greenhorn
It originated with cowboys who noticed the horns on young cattle had a greenish tint. So in the Old West, a person who was young or inexperienced in his craft or trade was called a greenhorn.
"To be" is not an idiom - it's a verb.
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.
A greenhorn is someone who is new in a job or new to a skill.
Greenhorn on the Frontier was created in 1974.
Billy Greenhorn died in 1995.
It's not an idiom - to cope means to deal with, or to handle
The idiom means impress someone is egg on
"Old hand" is an idiom meaning having lots of experience.