A quiet look by male bachelor shows confidence (6)
I believe the answer is:
aplomb
'confidence' is the definition.
(I've seen this before)
'a quiet look by male bachelor' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'look' becomes 'lo' (archaic exclamation meaning 'look!').
'by' means one lot of letters go next to another.
'male' becomes 'm' (common abbreviation).
'bachelor' becomes 'B' (abbreviation e.g. BA=Bachelor of Arts).
'a'+'p'+'lo'+'m'+'b'='APLOMB'
'shows' is the link.
(Other definitions for aplomb that I've seen before include "coolness is required" , "Self-satisfied poise" , "Pompous dignity or poise" , "'Poise, sang-froid (6)'" , "Calm self-assurance and poise" .)