| Dumb |
| Silly |
| Dorky |
| Dopey |
| Nutty |
| Inane |
| Absurd |
| Stupid |
| Idiotic |
| Dum-dum |
| Puerile |
| Fatuous |
| Foolish |
| Mindless |
| Pointless |
| Ludicrous |
| Fatheaded |
| Imbecilic |
| Brainless |
| Obstinate |
| Foolhardy |
| Laughable |
| Senseless? |
| Cockamamie |
| Ridiculous |
| Very silly |
| Sans sense |
| Harebrained |
| Really dumb |
| Blockheaded. |
| Totally dumb |
| Very foolish |
| Really silly |
| Preposterous |
| Knuckleheaded |
| Unintelligent |
| Not very smart |
| Featherbrained |
| Utterly absurd |
| Totally absurd |
| Ill-considered |
| Extremely silly |
| More than silly |
| Totally idiotic |
| Inanely foolish |
| Utterly foolish |
| Dumber than dumb |
| Just plain silly |
| Just plain stupid |
| Not very sensible |
| Completely idiotic |
| Totally ridiculous |
| Utterly ridiculous |
| Totally far-fetched |
| Completely senseless |
| Beneath consideration |
| Completely cockamamie |
| Literally, "like a donkey |
| Word from the Latin for "donkey-like |