perplexing (adj.)

• arcane
• baffling
• complex
• complicated
• confounding
• confusing
• convoluted
• cryptic
• disconcerting
• dismaying
• disturbing
• embarrassing
• enigmatic
• impenetrable
• incomprehensible
• intricate
• involved
• knotty
• labyrinthine
• mysterious
• mystifying
• paradoxical
• perturbing
• problematic
• puzzling
• recondite
• stupefying
• twisted
• unfathomable
• upsetting