Fail to justify fellow's trust (6)

I believe the answer is:

belief

'trust' is the definition.
(I've seen this before)

'fail to justify fellow's' is the wordplay.
'fail to justify' becomes 'belie' (I've seen this before).
'fellow' becomes 'f' (abbreviation - of a society etc.).
'belie'+'f'='BELIEF'

(Other definitions for belief that I've seen before include "Faith; confidence" , "Trust, faith (6)" , "Tenet, creed" , "Religious conviction" , "Credo" .)

I've seen this clue in The Independent.

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