An off-Broadway theatre is located close to Broadway, the main theatre district in New York.
...the city's most famous off-Broadway theater.
2. adjective [ADJECTIVE noun]
An off-Broadway play is less commercial and often more unusual than those usually staged on Broadway.
...adapted from the off-Broadway stage show of the same name.
off-Broadway in British English
adjective
1.
designating the kind of experimental, low-budget, or noncommercial productions associated with theatre outside the Broadway area in New York
2.
(of theatres) not located on Broadway
Compare off-off-Broadway
off-Broadway in American English
(ˈɔfˈbrɔdˌweɪ)
US
adjective
1.
designating, of, or produced in any theater located outside the main theatrical district in New York City and presenting professional productions that are often unconventional, experimental, low-cost, etc.
adverb
2.
in an off-Broadway theater or theaters
noun
3.
off-Broadway theaters and their productions collectively