1. One who manages an office or a company.
2. One who manages; a conductor or director
3. A person who conducts business or household affairs with economy and frugality; a good economist.

Any program that is designed to perform a certain set of housekeeping tasks related to computer operation, such as the maintenance of files. On the Macintosh, Manager (with a capital M) is used in the names of various separate portions of the computer’s operating system that handle input, output, and internal functions (for example, File Manager and Memory Manager).