odeon

As nouns the difference between amphitheater and odeon

is that amphitheater is (us) a semi-circular acoustic backdrop behind performers for an outdoor venue while odeon is odeon (music hall).

As nouns the difference between odeon and amphitheatre

is that odeon is an ancient Greek or Roman building used for performances of music and poetry while amphitheatre is an open, outdoor theatre, especially one from the classical period of ancient Greece.

As nouns the difference between theater and odeon

is that theater is a place or building, consisting of a stage and seating, in which an audience gathers to watch plays, musical performances, public ceremonies, and so on while odeon is an ancient Greek or Roman building used for performances of music and poetry.