| silly(adjective, ability, foolish, absurd, giddy) |
| dizzy(adjective, slang, ability, careless, silly) |
| empty-headed(adjective, slight, ability, careless, silly) |
| frivolous(adjective, slight, ability, careless, silly) |
| giddy(adjective, simple, ability, careless, silly) |
| goofy(adjective, frivolous, dizzy, frothy, flighty) |
| airheaded |
| harebrained(adjective, ability, careless, silly, foolish) |
| light-headed(adjective, silly, faint) |
| flighty(adjective, slight, ability, careless, silly) |
| lightheaded |
| brainless(adjective, simple, careless, foolish, stupid) |
| gaga(adjective, ability, informal, careless, foolish) |
| scatterbrained(adjective, ability) |
| birdbrained(adjective, slang, ability) |
| frothy(adjective, slight, ability, careless, trivial) |
| shallow(adjective, ignorant, unintelligent) |
| foolish |
| light |
| capricious(adjective, careless, unstable, unreliable, changeable) |