Climber succeeded after Tim and Alec somehow (8)
I believe the answer is:
clematis
'climber' is the definition.
(type of climbing plant)
'succeeded after tim and alec somehow' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'after' is a charade indicator (letters next to each other).
'and' is a charade indicator (letters next to each other).
'somehow' indicates anagramming the letters.
'tim' put after 'alec' is 'alectim'.
'alectim' anagrammed gives 'clemati'.
's' put after 'clemati' is 'CLEMATIS'.
(Other definitions for clematis that I've seen before include "bloomer" , "Climbing garden plant" , "Ornamental climbing plant" , "Ornamental climber" , "Garden climber" .)