| flaky(passionate, violent, thoughtless, abrupt, impetuous) |
| free(informal, casual, impulsive, spontaneous, unprepared) |
| hasty(passionate, violent, thoughtless, abrupt, impetuous) |
| headlong(passionate, violent, thoughtless, abrupt, impetuous) |
| hot-and-cold(passionate, violent, thoughtless, abrupt, impetuous) |
| immediate(free, informal, casual, impulsive, snap) |
| impetuous(thoughtless, unwary) |
| improvisation(noun, speech) |
| improvisatory(free, informal, casual, impulsive, snap) |
| improvised(free, casual, impulsive, spontaneous, unprepared) |
| improviso(free, informal, casual, impulsive, snap) |
| impulsive(adjective, thoughtless, spontaneous, impetuous, unplanned) |
| informal(free, casual, impulsive, snap, unprepared) |
| intuitive(passionate, violent, thoughtless, abrupt, impetuous) |
| jamming(free, informal, casual, impulsive, snap) |
| mad(passionate, violent, thoughtless, abrupt, impetuous) |
| made-up(free, informal, casual, impulsive, snap) |
| makeshift(free, informal, casual, impulsive, snap) |
| off-the-cuff(adjective, spontaneous, unprepared, impromptu, unrehearsed) |
| off the cuff(expression, free, informal, casual, snap) |