pensive in WordNet English dictionary

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 brooding melancholy young man";
   brooding  broody  contemplative  meditative  musing  pensive  pondering  reflective  ruminative 
   
2. showing pensive sadness
   "the sensitive and wistful response of a poet to the gentler phases of beauty"
   pensive  wistful