The most common and most likely answer to this crossword clue is the 8 letter word BROCCOLI
B
R
O
C
C
O
L
I
More clues leading to the result BROCCOLI
- Endlessly badger man requiring new green veg
- Colic Rob gets shifting cabbage
- . Terrible colic after Rob’s pickled vegetable!
- Cabbage badger doesn’t finish; firm, large one
- Vegetable, relative having caught cold, cut one
- Vegetable producer
- Badger king’s lacking coil-shaped vegetable
- Food Mr Forte left in British Island
- Brassica, some brown cabbage and cauliflower heads and cooking oil
- Sibling with constant abdominal pain failing to finish vegetable
Buddy explains!

The straight part
We know that "One of the Greens who took agent to the cinema? (" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one of the greens who took agent to the cinema? ( = broccoli.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BROCCOLI mean?
BROCCOLI noun- A plant, Brassica oleracea var. italica, of the cabbage family, Brassicaceae; especially, the tree-shaped flower and stalk that are eaten as a vegetable.