THESAURUS
complex, complicated, crabbed, cramp, difficult, garbled, hard, hard to understand, impracticable, impractical, inoperable, insuperable, insurmountable, intricate, jumbled, knotty, obfuscated, obscure, obscured, overtechnical, perplexed, scrambled, too much for, tough, unachievable, unattainable, uncompassable, undoable, uneffectible, unnegotiable, unperformable, unrealizable, unsurmountable, unworkable
