1. The quality of being spontaneous; acting or done without being planned or forced; natural and unrehearsed behavior
The spontaneity of her laughter made everyone smile.
A espontaneidade de seu riso fez todos sorrirem.
2. The capacity to act or speak in an unplanned, natural manner without external pressure or premeditation
Jazz musicians are praised for their spontaneity and improvisation.
Os músicos de jazz são elogiados por sua espontaneidade e improvisação.