Definition of: extemporaneous

(ik·stem′pə·rā′nē·əs) adjective
1. Done or made with little or no preparation; composed or uttered on the spur of the moment; unpremeditated.
2. Given to speaking without notes. [<LL extemporaneus <ex- out + tempus, temporis time]
—ex·tem′po·ra′ne·ous·ly adverb
—ex·tem′po·ra′ne·ous·ness noun Synonyms: extemporary, extempore, impromptu, improvised, offhand, unpremeditated. 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 thought has been prepared, and only the language and incidental treatment left to the suggestion of the moment, so that an extemporaneous speech is understood to be one that is not read or recited; impromptu keeps its original sense, denoting something that springs from the instant. Offhand is still more emphatic as to the readiness and freedom of the utterance. Unpremeditated is graver and more formal, denoting absolute want of preparation, but is too heavy a word to be applied to such apt, ready utterance as is generally designated by impromptu. Antonyms: elaborated, premeditated, prepared, read, recited, studied, written.