WordNet sense 1 (feeling or showing worry or solicitude):

concerned

WordNet sense 2 (so frightened as to be unable to move; stunned or paralyzed with terror):

petrified

WordNet sense 3 (thrown into a state of intense fear or desperation):

frightened, terrified

WordNet sense 4 (stricken with horror):

horrified

WordNet sense 5 (made afraid):

scared

WordNet sense 6 (experiencing or showing fear):

fearful

WordNet sense 7 (frightened into submission or compliance):

intimidated

WordNet sense 8 (in fear or dread of possible evil or harm):

apprehensive

WordNet sense 9 (experiencing a sudden sense of danger):

alarmed

WordNet sense 10 (struck with fear, dread, or consternation):

aghast, shocked

WordNet sense 11 (a pronunciation of afraid):

afeard, afeared