Antonyms of adj extemporaneous

1 sense of extemporaneous

Sense 1
ad-lib, extemporaneous, extemporary, extempore, impromptu, offhand, offhanded, off-the-cuff, unrehearsed -- (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")

INDIRECT (VIA unprepared) -> prepared -- (made ready or fit or suitable beforehand; "a prepared statement"; "be prepared for emergencies")

Similarity of adj extemporaneous

1 sense of extemporaneous

Sense 1
ad-lib, extemporaneous, extemporary, extempore, impromptu, offhand, offhanded, off-the-cuff, unrehearsed -- (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")
       => unprepared (vs. prepared) -- (without preparation; not prepared for; "unprepared remarks"; "the shock was unprepared"; "our treaty makers approached their immensely difficult problems unprepared"- R.E.Danielson)