The Collaborative International Dictionary
off-Broadway \off-Broadway\ prop. a. Of or pertaining to the professional theaters in Manhattan not in the Broadway area; performed in off-Broadway[1].
off-Broadway \off-Broadway\ prop. n.
A group of low-budget theaters located outside the Broadway area in Manhattan.
The professional drama presented in off-Broadway theaters.
Douglas Harper's Etymology Dictionary
1953, "experimental theater productions in New York City," from off (adv.) + Broadway. Even more experimental off-off-Broadway is attested from 1967.
Wiktionary
a. Of or pertaining to an off-Broadway theater, or a production mounted in one. n. (context often capitalized English) In the New York City area, a small theater with fewer than 300 seats, or a production in such a theater, usually away from the "Broadway" theater district, which operates under special rules from the theatrical unions, which permits mounting productions at a much lower cost.
WordNet
n. low-budget theaters located outside the Broadway area in Manhattan
Wikipedia
An Off-Broadway theatre is a professional venue in New York City with a seating capacity between 100 and 499. These theatres are smaller than Broadway theatres, but generally larger than Off-Off-Broadway theatres.
An "Off-Broadway production" is a production of a play, musical or revue that appears in such a venue and adheres to related trade union and other contracts.
Usage examples of "off-broadway".
Martin Mills has found a prospective angel, a wealthy, stagestruck businessman who he hopes will put up the money for an off-Broadway production.
In the past decade, my employers have included three carnivals, four roadside peep shows, two direct-to-video horror movie producers, and an artsy off-Broadway troupe bent on reviving Le Grand Guignol.
He rummaged rapidly through a couple of drawers until he found the color print of a rising red-headed young female off-Broadway dramatic talent who had recently refused to become America's Crown Princess of Sex Kittens for thirty days and he checked the envelope clipped to it to make sure three green nail clippings were still there.