adjective
BAD : He isn't matured enough to get married.
GOOD : He isn't mature enough to get married.
BAD : Replacing such a politically matured leader will not be easy.
GOOD : Replacing such a politically mature leader will not be easy.
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Use matured/mature when you are talking about wine, cheese etc: 'The whisky is kept here until it has matured/is mature.'
When you are talking about people, the usual word is mature : 'He's very mature for a boy of sixteen.'