Source : Webster's Revised Unabridged Dictionary (1913)

Fearsome \Fear"some\a.
   1. Frightful; causing fear. [Scotch] ``This fearsome wind.''
      --Sir W. Scott

   2. Easily frightened; timid; timorous. ``A silly fearsome
      thing.`` --B. Taylor

Source : WordNet®

fearsome
     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}, {frightening}, {horrendous}, {horrific},
            {terrible}]