midcap adjective 1noun 1forms 1 adjective1 •Having medium market capitalization, often defined as between 2 and 10 billion US dollars“You could’ve gone down to midcap stocks,” said Bruce T. Herring, group chief investment officer overseeing Fidelity Blue Chip Growth, the largest fund on the list. — 2007 noun1 •A stock with medium market capitalization. formsmidcaps