1. An unplanned or spontaneous exchange of items, roles, or positions created on the spot without prior arrangement
When the lead actor got sick, they did an improvised swap with the understudy.
Quando o ator principal ficou doente, fizeram uma troca improvizada com o substituto.
2. A quick, informal substitution or exchange made without preparation or formal agreement
The band members did an improvised swap of instruments during the performance.
Os membros da banda fizeram uma troca improvizada de instrumentos durante o show.