middle management

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The middle tier of management, usually including lower executives and employees who manage supervisors overseeing day-to-day operations.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun business In a large organization, the group of managers or administrators who occupy positions in the company hierarchy which, generally, are above the level of front-line supervisors but below the level of vice-presidents .