1brain·storm 
/ˈbreɪnˌstoɚm/ noun
plural brain·storms /ˈbreɪnˌstoɚm/ noun [count] 1 US : an idea that someone thinks of suddenly — usually singular ▪ Her latest brainstorm is to convert the garage into an apartment. —called also (chiefly Brit) brain wave 2 Brit : a temporary state of confusion : a period of unclear thinking
▪ I'm sorry—I must have been having a brainstorm when I wrote that.
▪ I'm sorry—I must have been having a brainstorm when I wrote that.
