What is another word for "extempore"?

Roget's Thesaurus (1911) lists these synonyms for "extempore": all, away, blink, breath, comes, creature, done, early, extemporaneous, extemporize, eye, fell, flash, haste, immediately, impromptu, improvisate, improvisation, improvisatore, improvisatory, improvise, improviso, impulse, impulsive, indeliberate, inspiration, instant, instanter, instinctive, jump, just, less, like, mind, moment, natural, occasion, offhand, once, one.