Very slender support for striker (10)
I believe the answer is:
matchstick
'very slender' is the definition.
I can't judge whether this defines the answer.
'support for striker' is the wordplay.
'support' becomes 'stick' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'striker' becomes 'match' (a match can be struck).
'stick' put after 'match' is 'MATCHSTICK'.
Can you help me to learn more?
(Other definitions for matchstick that I've seen before include "Long thin piece" , "Individual that's struck" , "Childishly pictured man" , "(Of a figure) drawn using thin straight lines" , "Very thin, like figures in Lowry paintings" .)