1. (noun)impromptu an extemporaneous speech or remark Antonyms: prepared
2. (adj)impromptu a short musical passage that seems to have been made spontaneously without advance preparation Antonyms: prepared
3. (adverb)ad-lib, extemporaneous, extemporary, extempore, impromptu, offhand, offhanded, off-the-cuff, unrehearsed with little or no preparation or forethought Synonyms: unwritten, unrehearsed, ad-lib, off-the-cuff, extemporaneous, extempore, offhand, spontaneous, extemporary, impromptu, offhanded Antonyms: prepared
4. (adverb)ad lib, ad libitum, spontaneously, impromptu without advance preparation Synonyms: ad libitum, spontaneously, impromptu, ad lib Antonyms: prepared
Synonyms, Thesaurus & Antonyms of 'impromptu'
English Synonyms and Antonyms
1. impromptu Extemporaneous, originally signifying of or from the time or occasion, has come to mean done or made with but little (if any) preparation, and is now chiefly applied to addresses of which the Synonyms: extemporaneous, extemporary, impromptu, offhand, extempore, improvised, unpremeditated Antonyms: elaborated, premeditated, prepared, read, recited, studied, written
Synonyms for impromptu 
