Boldness shown by opener very often (5)
I believe the answer is:
nerve
'boldness' is the definition.
(synonyms)
'shown by opener very often' is the wordplay.
'shown by' says the answer is hidden in the clue.
'NERVE' can be found hidden inside 'opener very often'.
(Other definitions for nerve that I've seen before include "Grit" , "Bodily fibre carrying sensation" , "displaying self-possession" , "Bundles of fibres in the body that transmit instructions" , "Mettle, daring" .)