Profound indignation not in fashion (7)
I believe the answer is:
outrage
'profound indignation' is the definition.
(I've seen this before)
'not in fashion' is the wordplay.
'not in' becomes 'out' ('out' is the opposite to 'in').
'fashion' becomes 'rage' (rage is a kind of fashion**).
'out'+'rage'='OUTRAGE'
(Other definitions for outrage that I've seen before include "A feeling of righteous anger" , "Very angry reaction" , "Appalled reaction" , "Gross injury" , "Gross affront to decency" .)