Writer so upset about cycling director Billy (5,5)
I believe the answer is:
oscar wilde
'writer' is the definition.
(I've seen this before)
'upset about cycling director billy' is the wordplay.
I cannot really see how this works, but
'about' could be 'ca' (circa) and 'ca' is present in the answer.
'director' could be 'd' (abbreviation eg in film reviews) and 'd' is found within the answer.
This explanation may well be incorrect...
'so' is the link.
Can you help me to learn more?
(Other definitions for oscar wilde that I've seen before include "dramatist" , "Irish-born writer and wit (1854-1900)" , "Irish writer and wit" , "He had nothing to declare but his genius" , "playwright" .)