e·pit·a·sis 
(ĭ-pĭtə-sĭs)
(ĭ-pĭtə-sĭs)n. pl. e·pit·a·ses (-sēz′)
The middle part of a play that develops the action leading to the catastrophe.
[Greek, stretching, intensity, from epiteinein, epita-, to stretch, intensify : epi-, epi- + teinein, to stretch; see ten- in the Appendix of Indo-European roots.]