Man runs away from rascally fellow (5)
I believe the answer is:
valet
'rascally fellow' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'man runs away from' is the wordplay.
'man' becomes 'Val'.
'runs away from' becomes 'et' (I can't justify this - if you can you should give a lot more credence to this answer).
'val'+'et'='VALET'
Can you help me to learn more?
(Other definitions for valet that I've seen before include "Male servant" , "Personal male assistant" , "Clean inside" , "'No man is a hero to his . . . . .'" , "Jeeves?" .)