1. Causing fear or dread or terror
   "horrendous explosions shook the city"
   - awful, dire, direful, dread, dreaded, dreadful, fearful, fearsome, frightening, horrific, terrible

See also: alarming

• Piperales
• piperazine
• piperidine
• piperin
• piperine
• piperocaine
• piperocaine hydrochloride
• pipestem clematis
• pipestone
• pipet
• pipette
• pipework
• pipewort
• pipewort family
• Pipidae
• Pipile
• Pipilo
• Pipilo erythrophthalmus
• piping
• piping crow
• piping crow-shrike
• piping guan
• piping plover
• pipistrel
• pipistrelle