WordWeb Online

1. Unable to express yourself clearly or fluently
   "incoherent with grief";
   - tongue-tied
    
2. Without logical or meaningful connection
   "a turgid incoherent presentation"
    
3. (physics) of waves having no stable definite or stable phase relation

See also: confused, disconnected, disjointed, disordered, fuzzy, garbled, illogical, inarticulate, irrational, scattered, unarticulate, unconnected, unlogical

Antonym: coherent

Encyclopedia: Incoherent