The most common and most likely answer to this crossword clue is the 9 letter word SEA-GREEN
I've seen this crossword clue in The Times
S
E
A
-
G
R
E
E
N
Buddy explains!
The straight part
We know that "shade/Geese ran" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shade/geese ran = sea-green.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.