Greenish-blue (9)
I believe the answer is:
turquoise
'greenish-blue' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for turquoise that I've seen before include "not quite green" , "Sort of blue" , "Aquamarine colour" , "Greenish blue; gemstone" , "Greenish-blue gem" .)