Open English Wordnet
Adjectives
(s)apprehensive, discerningquick to understand“a kind and apprehensive friend” (Nathaniel Hawthorne)
(s)apprehensive, worriedmentally 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”
(s)apprehensivein fear or dread of possible evil or harm“apprehensive for one's life”, “apprehensive of danger”