1) Beyond your understanding 2) Garbled 3) Impenetrable 4) Inarticulate 5) Incomprehensible 6) Inconceivable 7) Inexplicable 8) Not intelligible 9) Perplexing 10) Slurred 11) Thick 12) Uncomprehensible 13) Unfathomable 1) Clear as mud 2) Incoherent 3) Incomprehensible 4) Mumbled 5) Slurred 
[adj] - poorly articulated or enunciated, or drowned by noise
unintelligible 1. Poorly articulated or enunciated, or drowned out by noise; for example, unintelligible speech. 2. Not clearly understood or expressed.
adjective poorly articulated or enunciated, or drowned by noise; `unintelligible speech`
not intelligible; not capable of being understood.