| extraordinary(adjective, strange, unbelievable, implausible, unthinkable) |
| fabled(adjective, fake, false, imaginary, fanciful) |
| fabulous(adjective, fake, false, imaginary, fanciful) |
| fake(adjective, false, imaginary, fanciful, illusory) |
| false(adjective, fake, imaginary, fanciful, illusory) |
| fanciful(adjective, fake, false, imaginary, illusory) |
| far-fetched(unlikely, unbelievable, improbable) |
| far out(expression, adjective, unreasonable, dubious, unlikely) |
| farfetched(adjective, unreasonable, dubious, unlikely, flimsy) |
| fictitious(adjective, fake, false, imaginary, fanciful) |
| fictive(adjective, fake, false, imaginary, fanciful) |
| figmental(adjective, fake, false, imaginary, fanciful) |
| fishy(adjective, unreasonable, dubious, unlikely, flimsy) |
| flimsy(adjective, unreasonable, dubious, unlikely, unbelievable) |
| floating(adjective, silly, impractical, unlikely, unreal) |
| for the birds(expression, adjective, idiom, unreasonable, dubious) |
| full of holes(expression, adjective, idiom, unreasonable, dubious) |
| half-baked(adjective, silly, impractical, unlikely, unreal) |
| hallucinatory(adjective, fake, false, imaginary, fanciful) |
| ideal(adjective, fake, false, imaginary, fanciful) |