| devil-may-care(passionate, violent, thoughtless, abrupt, impetuous) |
| impromptu(free, casual, impulsive, spontaneous, unprepared) |
| ad lib(expression, free, informal, casual, unrehearsed) |
| autoschediastic(free, casual, impulsive, spontaneous, unprepared) |
| improv(free, informal, casual, impulsive, snap) |
| jumping the gun(expression, idiom, passionate, violent, thoughtless) |
| offhand(free, informal, casual, thoughtless, impetuous) |
| unpremeditated(free, passionate, violent, casual, abrupt) |
| automatic(free, informal, casual, thoughtless, impetuous) |
| ad-lib(free, casual, thoughtless, impulsive, spontaneous) |
| ad hoc(expression, free, informal, casual, unrehearsed) |
| at first glance(expression, free, informal, casual, snap) |
| by ear(expression, free, informal, casual, unrehearsed) |
| casual(free, informal, impulsive, spontaneous, unprepared) |
| emotional(passionate, violent, thoughtless, abrupt, impetuous) |
| expedient(free, informal, casual, impulsive, snap) |
| extemporaneous(adjective, free, casual, thoughtless, impulsive) |
| extemporary(free, casual, impulsive, spontaneous, unprepared) |
| extempore(free, casual, impulsive, spontaneous, unprepared) |
| fake(free, casual, impulsive, spontaneous, unprepared) |