Somewhat green and briefly in charge of a class (7)
I believe the answer is:
generic
'somewhat green and briefly in charge of a class' is the definition.
I can't tell whether this defines the answer.
'green and briefly in charge of a class' is the wordplay.
I cannot really see how this works, but
an anagram of 'green' is 'gener' which is present in the answer.
'in charge' could be 'ic' (abbreviation for 'in charge') and 'ic' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for generic that I've seen before include "Applicable to an entire class or group" , "Unspecific" , "Non-proprietary (drug)" , "cheap drug" , "Applicable to any member of a class" .)