Master switch
noun
a controlling switch over the actions within an entire electrical or fuel system, esp. one that can break the main supply in emergency situations
Read Also:
- Master warrant officer  noun 1. a noncommissioned officer in the Canadian forces junior to a chief warrant officer 
- Masterwork  [mas-ter-wurk, mah-ster-] /ˈmæs tərˌwɜrk, ˈmɑ stər-/ noun 1. . 
- Master-work  [mas-ter-wurk, mah-ster-] /ˈmæs tərˌwɜrk, ˈmɑ stər-/ noun 1. . n. c.1600, from master (n.) + work (n.). Probably based on a Dutch or German model. 
- Master-workman  noun 1. a worker in charge. 2. a person who is master of a craft. 
- Masterwort  [mas-ter-wurt, -wawrt, mah-ster-] /ˈmæs tərˌwɜrt, -ˌwɔrt, ˈmɑ stər-/ noun 1. a European plant, Astrantia major, of the parsley family, having pinkish-rose or white flower clusters with purplish bracts beneath. 
