green as grass
*green as grass
very green. (*Also: as ∼.) His face turned as green as grass just before he vomited.
green as grassBRITISH
If someone is as green as grass, they have little experience or knowledge of something and trust what other people tell them too easily. I was a newcomer to the sport and as green as grass. Note: It is much more common just to say that someone is green. They admit they were very green when they arrived.