1. [ adjective ] with little or no preparation or forethought
Synonyms: extemporaneous extemporary extempore off-the-cuff offhand offhanded unrehearsed ad-lib

"his ad-lib comments showed poor judgment" "an extemporaneous piano recital" "an extemporary lecture" "an extempore skit" "an impromptu speech" "offhand excuses" "trying to sound offhanded and reassurin

Related terms: unprepared
2. [ adjective ] in response to an unforeseen need
Synonyms: spur-of-the-moment

"an impromptu speech" "a spur-of-the-moment party"

Related terms: unprepared
3. [ noun ] an extemporaneous speech or remark

"a witty impromptu must not sound premeditated"

Related terms: address
4. [ adverb ] without advance preparation
Synonyms: ad_lib spontaneously ad_libitum

"he spoke ad lib"

5. [ noun ] (music,fine art) a short musical passage that seems to have been made spontaneously without advance preparation
Related terms: passage
Similar spelling:   imprimatur