ad-lib

Adjective

• 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
    

Noun

• remark made spontaneously without prior preparation
  • his ad-libs got him in trouble with the politicians
    

Verb

• perform without preparation
  • he extemporized a speech at the wedding
    

Related words

• Synonyms: 
  spontaneous , unwritten , extemporaneous , extemporary , extempore , impromptu , offhand , offhanded , off-the-cuff , unrehearsed , improvise , improvize , extemporize , extemporise