OLD THEATER can refer to two different crossword solutions: ODEON and ODEUM. ODEON is a type of theater that originated in the United Kingdom and is now found in many countries around the world. It is typically a large, single-screen cinema with a seating capacity of up to 1, 000 people. ODEUM is an ancient Greek theater, usually circular in shape, used for musical performances and theatrical productions. Both types of theaters have been around for centuries and are still popular today.