If you describe someone as jumped-up , you disapprove of them because they consider themselves to be more important than they really are. ( BRIT INFORMAL )
He’s nothing better than a jumped-up bank clerk!
ADJ : usu ADJ n [ disapproval ]
JUMPED-UP
Meaning of JUMPED-UP in English
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006