WordWeb Online

1. Deeply or seriously thoughtful
   "Byron lives on not only in his poetry, but also in his creation of the 'Byronic hero' - the persona of a reflective melancholy young man"
   - brooding, broody, contemplative, meditative, musing, pensive, pondering, ruminative
    
2. Capable of physically reflecting light or sound
   "a reflective surface"
    
3. Devoted to matters of the mind
   "the reflective type"

See also: intellectual, mirrorlike, reflect, reflecting, reflectively, reflectivity, specular, thoughtful

Antonym: nonreflective

Encyclopedia: Reflective