general museum; comprehensive museum
A museum that covers a wide range of fields, as opposed to a specialized museum. Often used in official names.
The National Museum of Nature and Science is one of the general museums.
This city has a general museum that covers history and science.
博物館 is a general term for 'museum', while 総合博物館 specifically emphasizes that it is a comprehensive or general museum covering multiple fields.
Compound of 総合 (そうごう, 'comprehensive') and 博物館 (はくぶつかん, 'museum').