Sharpness shown by a man with a cue maybe (6)
I believe the answer is:
acumen
'sharpness' is the definition.
(I've seen this in another clue)
'a man with a cue maybe' is the wordplay.
'with' means one lot of letters go next to another.
'maybe' indicates anagramming the letters.
'man' put after 'cue' is 'cueman'.
'cueman' is an anagram of 'ACUMEN'.
'shown by' acts as a link.
(Other definitions for acumen that I've seen before include "'Keenness, depth of perception (6)'" , "Shrewdness, good for business" , "Being sharp" , "Gumption" , "Cleverness in business" .)