Fantastic gene tea offers youth (7)
I believe the answer is:
teenage
'fantastic' is the definition.
Both the definition and answer are adjectives. Perhaps there's an association between them I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for teenage that I've seen before include "Eat gene to become young" , "Like a category of youngsters" , "Suitable for years 13-19" , "Juvenile" , "of seven difficult years" .)