[adverb], [adjective] [not gradable] - onto or on a stage for a performanceThe audience cheered as the band walked onstage for another encore.The documentary gives a fascinating account of life onstage and backstage.He's famous for his onstage destruction of his guitars.
ONSTAGE
Meaning of ONSTAGE in English
Cambridge English vocab. Кембриджский английский словарь. 2012