Ad lib and Impromptu

Ad lib

Ad lib adverb - Without advance preparation.
Usage example: he spoke ad lib

Impromptu is a synonym for ad lib in impulsive topic. In some cases you can use "Impromptu" instead the phrase "Ad lib" as an adverb or an adjective or a noun, when it comes to topics like spontaneous, extemporaneous, unrehearsed, improvised. popular alternative

Impromptu

Impromptu adverb - Without advance preparation.

Ad lib is a synonym for impromptu in extempore topic. You can use "Ad lib" instead the word "Impromptu" as an adverb or an adjective or a noun, if it concerns topics such as unrehearsed, spontaneously. popular alternative
Cite this Source
Impromptu and Ad lib. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/ad_lib/impromptu
Ad lib & Impromptu. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/ad_lib/impromptu>.
Impromptu or Ad lib. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/ad_lib/impromptu.
Google Ngram Viewer shows how "ad lib" and "impromptu" have occurred on timeline