Strut around showing confidence (5)
I believe the answer is:
trust
'confidence' is the definition.
(synonyms)
'strut around' is the wordplay.
'around' indicates anagramming the letters.
'strut' with letters rearranged gives 'TRUST'.
'showing' is the link.
(Other definitions for trust that I've seen before include "Have faith in, regard as reliable" , "Unit of NHS organisation" , "Faith - guardianship - after 10, the owners of the Guardian" , "Faith (in a business combination?)" , "Accept reliability of" .)