extemporaneous.

Produced or performed without fixed prepared wording or detailed rehearsal, often through immediate invention.

Use it for

Words that belong together

• extemporaneous speech
• extemporaneous remarks

On the page

Her extemporaneous remarks answered a question absent from the prepared speech.

The witness’s extemporaneous account changed as he found the sequence.

Usage notes

Primary category: literary. Forms: Comparative more extemporaneous; superlative most extemporaneous where gradation is meaningful. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings.