| occult(confidence, perplexity, mystery, abstruseness, inscrutableness) |
| occultism(perplexity, abstruseness, inscrutableness) |
| oracle(confidence, mystery) |
| password(confidence, mystery) |
| perplexity(abstruseness, inscrutableness) |
| puzzle(confidence, mystery) |
| puzzler(perplexity, abstruseness, inscrutableness) |
| rebus(perplexity, abstruseness, inscrutableness) |
| riddle(confidence, mystery) |
| rune(perplexity, abstruseness, inscrutableness) |
| runes(perplexity, abstruseness, inscrutableness) |
| skeleton in cupboard(expression, idiom, confidence, secret, perplexity) |
| skeleton in the cupboard(expression, idiom, confidence, mystery) |
| sphinx(perplexity, abstruseness, inscrutableness) |
| stumper(perplexity, abstruseness, inscrutableness) |
| teaser(perplexity, abstruseness, inscrutableness) |
| thriller(perplexity, abstruseness, inscrutableness) |
| tough nut to crack(expression, idiom, perplexity, abstruseness, inscrutableness) |
| unknown(confidence, mystery) |
| unrevealed(confidence, secret, mystery) |