naumachia
noun
nau·ma·chia nȯ-ˈmā-kē-ə 
-ˈma-
-ˈma- plural naumachiae nȯ-ˈmā-kē-ˌē
-kē-ˌī,
-ˈma-
or naumachias 1
: an ancient Roman spectacle representing a naval battle
2
: a place for naumachiae
Word History
Etymology
Latin, from Greek, naval battle, from naus ship + machesthai to fight — more at nave
First Known Use
1596, in the meaning defined at sense 1