Though young, possibly of some prominence (5)
I believe the answer is:
minor
'though young' is the definition.
'minor' can be an answer for 'young' (thesaurus). I am not certain of the 'though' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for minor that I've seen before include "Slight; little known" , "Person not yet of legal age" , "Not major" , "Of small importance" , "Junior" .)