| fallacious(adjective, false, foolish, unreasonable, ill) |
| fanciful(adjective, careless, unreasonable, unpredictable, changeable) |
| fleeting(adjective, present, short, limited, brief) |
| flexible(adjective, changeable, fickle, variable, volatile) |
| flickering(adjective, irregular, disturbed, changeable, variable) |
| flitting |
| fly-by-night(adjective, careless, loose, foolish, uncertain) |
| foolish(careless, stupid, unreasonable, fantastic, unthinking) |
| freakish(adjective, change, continue, careless, unreasonable) |
| fugacious(adjective, present, short, limited, brief) |
| liquid(adjective, free, travel, traveling, movable) |
| lubricious(adjective, smooth, careless, lively, uncertain) |
| momentary(adjective, present, short, limited, unpredictable) |
| nuts(mad, insane, psychiatric) |
| paranoid |
| questionable(adjective, open, obscure, uncertain, unsettled) |
| scatterbrained(careless, stupid, immoral, thoughtless, unreliable) |
| shifty(adjective, weak, uncertain, sensitive, doubtful) |
| short-lived(adjective, short, limited, brief, rot) |
| short-term(adjective, temporary) |