| impolitic(adjective, sharp, rough, rude, careless) |
| improvised(adjective, impulsive) |
| mercurial(fast, quick, restless, fiery, excitability) |
| presto(adjective, hot, fast, quick, rapid) |
| querulous(adjective, difficult, cross, passionate, irritable) |
| rapid-fire(adjective, prompt, fast, quick, urgent) |
| sharp(adjective, rough, careless, short, quick) |
| short-tempered(cross, irritable, touchy, testy, tetchy) |
| silly(adjective, slight, detail, foolish, trivial) |
| surprising |
| temporary(adjective, time, transient, transitory, short-lived) |
| unannounced |
| untimely |
| winged(hot, fast, quick, nimble, speedy) |
| zippy(adjective, urgent) |
| acute(adjective, sudden) |
| ad-lib(thoughtless, impetuous, unwary) |
| adventurous(adjective, careless, wild, thoughtless, impulsive) |
| alacritous(adjective, prompt, fast, quick, summary) |
| antsy(adjective, keen, violent, anxious, eager) |