Son in peace mad to get out (6)
I believe the answer is:
escape
'get out' is the definition.
(I've seen this before)
'son in peace mad' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'in' indicates putting letters inside.
'mad' indicates anagramming the letters.
'peace' anagrammed gives 'ecape'.
's' inserted inside 'ecape' is 'ESCAPE'.
'to' is the link.
(Other definitions for escape that I've seen before include "Get away from confinement" , "Decamp" , "See cap (anag.)" , "Get free from confinement or control" , "Abscond, flee" .)