Colourful bloke entertaining lad in apartment (10)
I believe the answer is:
flamboyant
'colourful bloke entertaining lad in apartment' is the definition.
I can't tell whether this definition defines the answer.
'colourful bloke entertaining lad in apartment' is the wordplay.
'colourful bloke' becomes 'man' (I've seen this in other clues. I am not sure about the 'colourful' bit.**).
'entertaining' is an insertion indicator.
'lad' becomes 'boy' (I've seen this before).
'in' is an insertion indicator.
'apartment' becomes 'flat' ('flat' can be a synonym of 'apartment').
'man' placed around 'boy' is 'mboyan'.
'mboyan' put within 'flat' is 'FLAMBOYANT'.
(Other definitions for flamboyant that I've seen before include "baroque" , "Showy" , "Exuberant" , "Gay" , "Ostentatious, colourful" .)