incoherent
     adj 1: without logical or meaningful connection; "a turgid
            incoherent presentation" [ant: {coherent}]
     2: unable to think or express your thoughts in a clear or
        orderly manner; "incoherent with grief"
     3: unable to express yourself clearly or fluently; "felt
        tongue-tied with embarrassment"; "incoherent with grief"
        [syn: {tongue-tied}]
Source: WordNet® 2.0