| perplexing(adjective, obscure, dark, sophisticated, mysterious) |
| ambiguous(adjective, dark, uncertain, blank, mysterious) |
| baffling(adjective, solid, strange, dense, unfathomable) |
| cryptical |
| involved(adjective, complicated) |
| recondite(adjective, obscure, dark, uncertain, sophisticated) |
| intricate(adjective, complicated) |
| cabalistic(adjective, solid, strange, blank, dense) |
| esoteric(adjective, obscure, strange, mysterious, supernatural) |
| hard |
| impassive(adjective, dull, quiet, cool, moderate) |
| indecipherable(adjective, dark, uncertain, mysterious, unfathomable) |
| secret(adjective, dark, strange, uncertain, blank) |
| calm(adjective, quiet, cool, still, peaceful) |
| enigmatical(adjective, solid, strange, supernatural, dense) |
| expressionless(adjective, dull, dead, blank, impassive) |
| hidden(adjective, obscure, solid, strange, sophisticated) |
| incognizable |
| mystical(adjective, strange, supernatural, spiritual, inexplicable) |
| unknowable(adjective, solid, strange, blank, dense) |