WordWeb Online

1. Undergoing no change when acted upon
   "entirely unaffected by each other's writings"; "fibers remained apparently unaffected by the treatment"
    
2. Unaware of or indifferent to
   - insensible
    
3. Emotionally unmoved
   - unmoved, untouched
    
4. Free of artificiality; sincere and genuine
   "an unaffected grace"

See also: affectedness, effeteness, immune, insensitive, lifelike, natural, superior, unaffectedness, uncontrived, unemotional, unimpressed, uninfluenced, unmannered, unselfconscious, unstilted, unstudied, unswayed, untouched

Antonym: affected