apprehensive in WordNet English dictionary

1. in fear or dread of possible evil or harm
   "apprehensive for one's life"; "apprehensive of danger"
   apprehensive 
   
2. quick to understand
   "a kind and apprehensive friend"- Nathaniel Hawthorne
   apprehensive  discerning 
   
3. mentally upset over possible misfortune or danger etc
   "apprehensive about her job"; "not used to a city and worried about small things"; "felt apprehensive about the consequences"
   apprehensive  worried