Broad sample of new ideas (4)
I believe the answer is:
wide
'broad' is the definition.
(I know that broad can be written as wide)
'sample of new ideas' is the wordplay.
'sample of' indicates a hidden word (an extract or sample of the clue).
'WIDE' is hidden in the letters of 'new ideas'.
(Other definitions for wide that I've seen before include "Expansive" , "Extending far" , "shrewd and shifty" , "Broad; cricket delivery" , "Spacious; an extra" .)