It means the person looks sick. Usually they are pale and green in the face.
The idiom "stuffed to the gills" means that something is completely full or packed to its maximum capacity. It is often used to describe a situation where there is no more space left.
"to be green" is to be new at something, inexperienced, a rookie or novice
An idiom that means prone to nausea might be "green at the gills." This refers to the fact that your face pales when you feel nauseated. Some people thought that color was a pale green, and this started the phrase. You might also hear "an upset stomach." This can mean any sort of discomfort in the abdominal area, from nausea to diarrhea.
It's not an idiom. It's American slang for money, because American paper bills are green (and they fold when you put them in your pocket).
It means swearing violently and creatively.
This means to feel nauseous or seasick.
It is just an exaggerated way of saying something happens quite often - it is hyperbole, not an idiom.
It means someone who is very good at things like gardening and growing things.
It means that there is not enough for everyone. It's insufficient.
To turn completely around and head back in the direction you came from.
Nothing. Perhaps you are thinking of beating around the bush, which means to avoid the topic of conversation.
It's not really an idiom. It means "what are you thinking about."