WordWeb Online

1. Highly educated; having extensive information or understanding
   "a knowledgeable critic";
   - knowing, learned, lettered, well-educated, well-read, knowledgable, well-versed
    
2. Alert and fully informed
   "surprisingly knowledgeable about what was going on";
   - knowing, knowledgable
    
3. Thoroughly acquainted through study or experience
   "knowledgeable about the technique of painting";
   - intimate, versed, knowledgable

See also: educated, experienced, experient, informed

Encyclopedia: Knowledgeable