Greenery is green leaves and plants, taken as a mass — the green stuff itself, not one named tree or flower. You use it for the leafy look of a place: trees along a street, bushes in a park, cut branches brought indoors for a festival. Florists and people decorating a room talk about greenery when they mean leaves and stems used to fill a space, not the flowers. It is a friendly, slightly soft word. You do not normally count it: we say some greenery or a bit of greenery, not three greeneries. It does not mean the colour green on its own. It also does not mean a person who sells fruit and vegetables; that is a greengrocer, a different word, though it shares the same green.