thea, theatr
It depends on what you mean by 'four letter word'. Thea has four letters, so yes it is. It is not a swear word, so it's not that kind of 'four letter word'.
amph i thea tre.
Its θέα (thea). Not to be confused with θεά meaning goddess.
Thea Gottschalk's birth name is Thea Hauer.
Thea Holme's birth name is Thea Johnston.
Thea Samuelson's birth name is Thea Connors.
Its σκηνικό (skiniko). Another definition would be θέα (thea).
The Greek root word for theatre is "theatron," which means "a place for viewing."
Thea Ringen's birth name is Thea Jondal Ringen.
Thea Aichbichler's birth name is Thea Aichbichler Mohr.
Thea Trinidad's birth name is Thea Megan Trinidad.