ad lib

without advance preparation

• “he spoke ad lib”

remark made spontaneously without prior preparation

• “his ad-libs got him in trouble with the politicians”

said or done without having been planned or written in advance

• “he made a few ad-lib remarks”

with little or no preparation or forethought

• “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 reassuring”
• “an off-the-cuff toast”
• “a few unrehearsed comments”

perform without preparation

• “he extemporized a speech at the wedding”