[N-UNCOUNT 不可数名词]成年Adulthood is the state of being an adult.
Few people nowadays are able to maintain friendships into adulthood.
如今很少有人能将友谊维持到成年。
Oxford
adult·hoodAWL/ˈædʌlthʊd; NAmEˈædʌlthʊd//əˈdʌlthʊd; NAmEəˈdʌlthʊd/noun[uncountable ]the state of being an adult 成年◆a child reaching adulthood已成年的孩子adult·hood/ˈædʌlthʊd; NAmEˈædʌlthʊd/