epitasis
noun
epit·a·sis i-ˈpi-tə-səs 
plural epitases i-ˈpi-tə-ˌsēz
: the part of a play developing the main action and leading to the catastrophe
Word History
Etymology
borrowed from Greek epítasis "stretching, increase in intensity, development of the plot of a play," from epita-, variant stem of epiteínein "to stretch on or over, tighten, increase in intensity" (from epi- epi- + teínein "to stretch, extend, spread") + -sis -sis — more at tenant entry 1
First Known Use
1583, in the meaning defined above