| unexpected(passionate, violent, thoughtless, abrupt, impetuous) |
| unmeditated(passionate, violent, thoughtless, abrupt, impetuous) |
| unpredictable(passionate, violent, lively, thoughtless, changeable) |
| unpremeditated(passionate, violent, thoughtless, abrupt, impetuous) |
| unprompted(passionate, violent, thoughtless, abrupt, impetuous) |
| unquestionable |
| ups and downs(adjective, change, instability) |
| vacillant |
| vacillating(adjective, variable) |
| variable(adjective, lively, active, impulsive, unpredictable) |
| violent(passionate, thoughtless, abrupt, impetuous, unwary) |
| volatile(adjective, lively, impulsive, unpredictable, changeable) |
| winging it(expression, passionate, violent, thoughtless, abrupt) |
| yo-yo(lively, unpredictable, changeable, temperamental, resilient) |
| yoyo(adjective, variable) |
| active(lively, unpredictable, changeable) |
| airy(impulsive, unpredictable, explosive) |
| bobbing(adjective, variable) |
| bolt upright |
| brash(thoughtless, impetuous, unwary) |