dead manβs switch
n.β Β«This pyrotechnic crew wonβt be sitting around, though, until the “dead manβs switch,” as it is called, is clicked to start the show. Until then, theyβre moving boxes, cutting tape and sorting through thousands of fireworks.Β» ββBehind-the-Scenes with Pyrotechnics” by Britney Glaser KPLC-TV (Lake Charles, Lousiana) July 4, 2007. (source: Double-Tongued Dictionary)