Observe what is captured by daring (6)
I believe the answer is:
behold
'observe' is the definition.
(thesaurus)
'what is captured by daring' is the wordplay.
'what' becomes 'eh' (I've seen this in other clues).
'is captured by' is an insertion indicator.
'daring' becomes 'bold' (I've seen this before).
'eh' placed within 'bold' is 'BEHOLD'.
(Other definitions for behold that I've seen before include "See! Look!" , "Archaic injunction to look" , "Look to the poet" , "See, with attention" , "Archaic word for see or observe" .)