adj. unstudied, unpremeditated, extempore, extemporary, impromptu, improvised, spontaneous, unrehearsed, extemporized, unprepared, unplanned, unscripted, offhand, ad lib, extempore, Colloq off the cuff Though extraordinarily well-organized, Charlotte's speech was entirely extemporaneous
EXTEMPORANEOUS
Meaning of EXTEMPORANEOUS in English
Oxford thesaurus English vocab. Английский словарь Оксфорд тезаурус. 2012