Deny wife’s escaped from prison once (6)
I believe the answer is:
negate
'deny' is the definition.
(negate can mean to deny or refute)
'wife's escaped from prison once' is the wordplay.
'wife' becomes 'w' (abbreviation).
'escaped from' is a deletion indicator.
'prison once' becomes 'newgate' (historical prison).
'newgate' with 'w' taken away is 'NEGATE'.
(Other definitions for negate that I've seen before include "Render null or disprove" , "Nullify - deny the existence of" , "disallow!" , "Deny the truth of" , "Render ineffective" .)