ˌover-aˈchiever BrE AmE noun [countable]
someone who works very hard to be successful, and is very unhappy if they do not achieve everything they want to OPP underachiever
ˌover-aˈchiever BrE AmE noun [countable]
someone who works very hard to be successful, and is very unhappy if they do not achieve everything they want to OPP underachiever
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012