Knitting clothes endlessly, and making what Olympian Daley was best at? (9)
I believe the answer is:
decathlon
'what olympian daley was best at?' is the definition.
(as in decathlete Daley Thompson)
'knitting clothes endlessly and' is the wordplay.
'knitting' is an anagram indicator.
'endlessly' means to remove the last letter.
'clothes' with its final letter taken away is 'clothe'.
'clothe'+'and'='clotheand'
'clotheand' with letters rearranged gives 'DECATHLON'.
'making' acts as a link.
(Other definitions for decathlon that I've seen before include "Sporting event with 10 disciplines" , "Series of events" , "sporting contest" , "Athletic event" , "Latched on to athletic competition of 10 events" .)