Have more, but feeling less on leaving? (9)
I believe the answer is:
outnumber
'have more but' is the definition.
I can't tell whether this defines the answer.
'feeling less on leaving?' is the wordplay.
'feeling less' becomes 'number' (more numb).
'on' means one lot of letters go next to another.
'leaving?' becomes 'out' (I can't justify this - if you can you should believe this answer much more).
'number' put after 'out' is 'OUTNUMBER'.
Can you help me to learn more?
(Other definitions for outnumber that I've seen before include "Have more (eg troops) than" , "Be too many for in contest or conflict" , "Be more numerous than" , "Be in the majority" , "Exceed numerically" .)