Synonyms: elusive
Definition: skillful at eluding capture
Usage: a cabal of conspirators, each more elusive than the archterrorist- David Kline
Similar words: artful
Definition: marked by skill in achieving a desired end especially with cunning or craft
Usage: the artful dodger; an artful choice of metaphors
Synonyms: elusive, tough, baffling, problematic, problematical, knotty
Definition: making great mental demands; hard to comprehend or solve or believe
Usage: a baffling problem; I faced the knotty problem of what to have for breakfast; a problematic situation at home
Similar words: difficult, hard
Definition: not easy; requiring great physical or mental effort to accomplish or comprehend or endure
Usage: a difficult task; nesting places on the cliffs are difficult of access; difficult times; why is it so hard for you to keep a secret?
Synonyms: elusive
Definition: difficult to describe
Usage: a haunting elusive odor
Similar words: unidentifiable
Definition: impossible to identify
Definition: difficult to detect or grasp by the mind or analyze
Usage: his whole attitude had undergone a subtle change; a subtle difference; that elusive thing the soul
Similar words: impalpable
Definition: imperceptible to the senses or the mind
Usage: an impalpable cloud; impalpable shadows; impalpable distinctions; as impalpable as a dream