one-act

The compound "one-act" is a straightforward descriptive formation in Modern English. The first element, "one," originates from the Proto-Germanic ainaz, carrying the fundamental meaning of singularity. The second element, "act," derives from the Latin 'actus', which referred to a driving force or a performance, stemming from the verb 'agere' (to do, to drive). In theatrical terminology, an "act" became established as a principal division of a play. By combining these two native and borrowed elements, "one-act" logically denotes a dramatic work confined to a single such division, emphasizing its brevity and unified structure compared to multi-act plays.

Structure: one (single) + act (dramatic division) - one: From Old English 'ān', meaning "one, single, alone". Its functional role is as a numerical adjective modifying the noun. - act: From Latin 'actus' (a doing, a driving), via Old French 'acte'. Its functional role is as a noun meaning a main division of a play.