From Longman Dictionary of Contemporary Englishsubplotsub‧plot /ˈsʌbplɒt $ -plɑːt/ noun [countable] ALAMa plot (=set of events) that is connected with but less important than the main plot in a story, play etc the novel’s romantic subplot
Examples from the Corpus
subplot• A subplot plays in the background, where two men meet, light a cigarette and separate.• The story of water and Los Angeles divides itself into countless subplots.• He keeps wandering into minor subplots, about a flamenco dancer and a dancing doctors demonstration.• In between the storms, a mix of subplots puddle up the movie.• He has a second reason, spelled out in one of several stagy subplots.• The first scene of the subplot also opposes and discriminates its protagonists.• When subplots or scenes of local color are introduced, they relate to the main plot in a fundamental way. 