| airheaded(adjective, unstable, unreliable, changeable, fickle) |
| birdbrained(adjective, unstable, unreliable, changeable, fickle) |
| brainless(adjective, careless, silly, unsteady, inconstant) |
| empty-headed(adjective, careless, silly, unstable, unreliable) |
| flighty(adjective, careless, lively, active, unpredictable) |
| gaga(adjective, careless, lively, active, unstable) |
| harebrained(adjective, careless, unstable, unreliable, changeable) |
| mad(lively, unpredictable, changeable, temperamental, resilient) |
| absurd |
| asinine |
| balmy |
| bemused(adjective, careless, silly, unsteady, inconstant) |
| blowing hot and cold(expression, idiom, lively, unpredictable, changeable) |
| boneheaded |
| brain-dead |
| buoyant(lively, unpredictable, changeable, resilient) |
| capricious(adjective, careless, lively, active, unstable) |
| careless(adjective, silly, impulsive, unsteady, inconstant) |
| changeable(adjective, careless, lively, active, unstable) |
| changeful(adjective, careless, silly, unsteady, inconstant) |