Source : Webster's Revised Unabridged Dictionary (1913)

Frighten \Fright"en\, v. t. [imp. {Frightened}; p. pr. & vb. n.
   {Frightening}.] [See {Fright}, v. t.]
   To disturb with fear; to throw into a state of alarm or
   fright; to affright; to terrify.

         More frightened than hurt.               --Old Proverb.

Source : WordNet®

frightening
     n : to inspire with fear [syn: {terrorization}, {terrorisation}]

frightening
     adj : causing fear or dread or terror; "the awful war"; "an awful
           risk"; "dire news"; "a career or vengeance so direful
           that London was shocked"; "the dread presence of the
           headmaster"; "polio is no longer the dreaded disease it
           once was"; "a dreadful storm"; "a fearful howling";
           "horrendous explosions shook the city"; "a terrible
           curse" [syn: {awful}, {dire}, {direful}, {dread(a)}, {dreaded},
            {dreadful}, {fearful}, {fearsome}, {horrendous}, {horrific},
            {terrible}]