Means a short chap (5)
I believe the answer is:
agent
'means' is the definition.
(I've seen this in another clue)
'a short chap' is the wordplay.
'short chap' becomes 'gent' (both can mean a man. I am not sure about the 'short' bit.).
'a'+'gent'='AGENT'
Can you help me to learn more?
(Other definitions for agent that I've seen before include "One does business on behalf of another" , "Instrument" , "Representative - means" , "Performer's manager" , "Middleman" .)