Strongly affect by leaving one's mark? (7)
I believe the answer is:
impress
'strongly affect' is the definition.
'impress' can be an answer for 'affect' (impressing is a kind of affecting). I am not sure about the 'strongly' bit.
'by leaving one's mark?' is the wordplay.
'by' is a charade indicator (letters next to each other).
'leaving' becomes 'press' (I can't explain this - if you can you should give a lot more credence to this answer).
'one' becomes 'i' (Roman numeral).
'mark?' becomes 'm'.
'i'+'m'='im'
'press' put after 'im' is 'IMPRESS'.
Can you help me to learn more?
(Other definitions for impress that I've seen before include "Inspire - engrave" , "Make mark or pattern by applying pressure" , "Stamp, emboss" , "Make a lasting effect (on)" , "Inspire respect, stamp" .)