1. A spontaneous or unplanned statement or announcement made without prior preparation or thought
The president made an impromptu declaration about the new policy during the press conference.
O presidente fez uma declaração improvisada sobre a nova política durante a coletiva de imprensa.
2. An extemporaneous expression of opinion, intention, or feeling delivered without rehearsal
Her impromptu declaration of love surprised everyone at the wedding reception.
Sua declaração improvisada de amor surpreendeu a todos na recepção do casamento.