clear as mud

1. Murky, obscure, totally unclear, as in The translation of these directions is clear as mud. This ironic phrase always indicates that something is far from clear. [Early 1800s]

Related Words

• baffling 
• impenetrable 
• inconceivable 
• mystifying www.thesaurus.com
• opaque 
• puzzling 
• unfathomable 
• unimaginable 
• unintelligible