21
promptly(adjective, adverb, fast, immediately, quickly)
21
immediately(adverb, quick, now, directly, quickly)
21
quickly(adjective, adverb, fast, immediately, rapidly)
19
at once(expression, idiom, adverb, directly, immediately)
18
speedily(adverb, fast, quickly, rapidly)
16
directly(adverb, fast, quickly, rapidly)
16
fast(adjective, adverb, fast, immediately, quickly)
16
swiftly(adverb, fast, quickly, rapidly)
15
rapidly(adverb, fast, quickly)
14
apace(adverb, fast, quickly, rapidly)
13
hastily(adverb, fast, quickly, rapidly)
13
instantaneously(adverb, fast, quickly, rapidly)
13
right away(verb, expression, adverb, phrasal verb, now)
13
without delay(expression, idiom, adverb, directly, immediately)
12
instantly(adverb, early, now, directly, immediately)
12
soon(adjective, adverb, quick, immediate, directly)
11
in nothing flat(expression, idiom, adverb, hot, fast)
11
quick(adjective, adverb, hot, fast, speedy)
10
on the double(expression, idiom, adverb, hot, quick)
9
forthwith(adverb, now, directly, immediately, quickly)
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APASmart Define. (2015). pronto thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/pronto/thesaurus/synonyms
ChicagoSmart Define. 2015. "pronto thesaurus" https://smartdefine.org/pronto/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, pronto thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/pronto/thesaurus/synonyms>.
MLASmart Define. "pronto thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/pronto/thesaurus/synonyms>