Ground (someone)
To take away someone's privileges (usually used for teenagers).The girl was grounded by her parents because she came home late too often.
Ground floor
The first or best chance (especially in a business).The video store was a good investment and I was happy to get in on the ground floor.
Green with envy
To be very jealous, to be full of envy.The little girl was green with envy when she saw her friend`s new bicycle.
A green thumb
The skill to make plants grow.The man has a green thumb and has a very beautiful garden.
Green around the gills
To look sick.My colleague was looking a little green around the gills when he came to work today.
Green
To be inexperienced or immature.The new employee is green and does not know his job very well.
Greatest thing since sliced bread
The best thing that there ever was.The new digital camera is the greatest thing since sliced bread.
Greasy spoon
A small and cheap eating place with basic but not great food.We went to a greasy spoon for breakfast because the other restaurants were closed.
Grease (someone`s) palm
To pay money to someone for some special favor.We had to grease the border guard`s palm in order to enter the country.
Good sport
A person who loses a competition or game without complaining.My friend is a good sport and he never complains about losing.