adj. incapable of being explained or accounted for; "inexplicable errors"; "left the house at three in the morning for inexplicable reasons"

adj. lacking clarity of meaning; causing confusion or perplexity; "sent confusing signals to Iraq"; "perplexing to someone who knew nothing about it"; "a puzzling statement"

adj. not clear to the understanding; "I didn't grasp the meaning of that enigmatic comment until much later"; "prophetic texts so enigmatic that their meaning has been disputed for centuries"

adj. skillful at eluding capture; "a cabal of conspirators, each more elusive than the archterrorist"- David Kline

adj. impossible to understand; "impenetrable jargon"

adj. making great mental demands; hard to comprehend or solve or believe; "a baffling problem"; "I faced the knotty problem of what to have for breakfast"; "a problematic situation at home"

adj. difficult to penetrate; incomprehensible to one of ordinary understanding or knowledge; "the professor's lectures were so abstruse that students tended to avoid them"; "a deep metaphysical theory"; "some recondite problem in historiography"

adj. beyond what is ordinary or usual; highly unusual or exceptional or remarkable; "extraordinary authority"; "an extraordinary achievement"; "her extraordinary beauty"; "enjoyed extraordinary popularity"; "an extraordinary capacity for work"; "an extraordinary session of the legislature"

adj. very great or intense; "a terrific noise"; "a terrific thunderstorm storm"; "fought a terrific battle"

adj. complicated in structure; consisting of interconnected parts; "a complex set of variations based on a simple folk melody"; "a complex mass of diverse laws and customs"

adj. difficult to analyze or understand; "a complicated problem"; "complicated Middle East politics"

adj. of depth; not capable of being sounded or measured

adj. capable of being explicated or accounted for; "explicable behavior"