Adverb
without prior preparation
Source: WordNetI'm terrible at speaking extemporaneously about my work - I get completely tongue-tied and consumed with fear. Annie Baker
I don't enjoy hearing the sound of my voice. The most important things for me are impossible to articulate extemporaneously. Annie Baker
he spoke extemporaneously Source: Internet
Also, I gradually developed the ability to speak extemporaneously". Source: Internet
However, he had strong support from the existing faculty, who suggested that the candidates speak extemporaneously on any topic of the candidate’s choice. Source: Internet
In Hearst's taped recordings, used to announce demands and conditions, Hearst can first be heard extemporaneously expressing SLA ideology on day 13 of her capture. Source: Internet