African runner with nothing on way, being affluent (7)
I believe the answer is:
ostrich
'african runner' is the definition.
'with nothing on way being affluent' is the wordplay.
'with' means one lot of letters go next to another.
'nothing on' becomes 'o' (I've seen this in other clues).
'way' becomes 'st'.
'being affluent' becomes 'rich' ('rich' can be similar in meaning to 'affluent').
'o'+'st' is 'ost'.
'ost'+'rich'='OSTRICH'
(Other definitions for ostrich that I've seen before include "World's largest bird" , "A bird for the shirt co." , "The head-in-the-sand bird" , "Large flightless bird of Africa" , "Rich sot seeks large bird" .)