Chalet is planned to accommodate leader of team sport (9)
I believe the answer is:
athletics
'sport' is the definition.
(I know that sport can be written as athletics)
'chalet is planned to accommodate leader of team' is the wordplay.
'planned' is an anagram indicator.
'to accommodate' means one lot of letters goes inside another.
'leader of' indicates taking the first letters.
The initial letter of 'team' is 't'.
'chalet'+'is'='chaletis'
'chaletis' with letters rearranged gives 'athleics'.
'athleics' going around 't' is 'ATHLETICS'.
(Other definitions for athletics that I've seen before include "Running and jumping" , "Lithe acts performed in physical sports" , "Oldham and Charlton?" , "Olympic events" , "Track and field sport" .)