fearsome

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”