| slow(adjective, dull, simple, heavy, silly) |
| feeble-minded(adjective, dull, simple, slow, foolish) |
| taciturn(adjective, calm, close, quiet, soft) |
| wordless(adjective, calm, quiet, humble, speak) |
| asinine(adjective, silly, foolish, stupid, crazy) |
| dopey(adjective, dull, simple, slang, ability) |
| fatuous(adjective, foolish, crazy, insane, impractical) |
| mum(adjective, quiet, soft, aloof, reticent) |
| quiet(verb, adjective, calm, dull, close) |
| pigeon-livered(adjective, calm, quiet, humble, shy) |
| goofy(adjective, foolish, stupid, impractical, half-baked) |
| simple(adjective, dull, slow, silly, foolish) |
| half-witted(adjective, dull, simple, slow, silly) |
| humble(adjective, calm, quiet, shy, silent) |
| imbecilic(adjective, dull, simple, slow, silly) |
| inane(adjective, dull, simple, slow, silly) |
| slow-witted(adjective, dull, slow, stupid, impassive) |
| stolid(adjective, dull, simple, slow, foolish) |
| silly(adjective, foolish, stupid, crazy, vague) |
| crazy(adjective, foolish, impulsive, insane, unintelligent) |