three-act play; three-act work
Refers to a dramatic work structured in three acts, such as a play, opera, or sometimes a film. Common in theatrical contexts.
His new work is a three-act tragedy.
A famous three-act play will be performed at this theater next month.
Compound of 三 (three), 幕 (act), and 物 (thing, work). The term follows the pattern of other act-count words like 一幕物 and 二幕物.