One still growing green tea abroad (8)
I believe the answer is:
teenager
'one still growing' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'green tea abroad' is the wordplay.
'abroad' is an anagram indicator.
'green'+'tea'='greentea'
'greentea' with letters rearranged gives 'TEENAGER'.
Can you help me to learn more?
(Other definitions for teenager that I've seen before include "youth, perhaps" , "one that's not yet made a score?" , "Adolescent" , "Youngster" , "hormonal problem?" .)