- hideous, horrid, horrific, outrageous - grossly offensive to decency or morality; causing horror; "subjected to outrageous cruelty"; "a hideous pattern of injustice"; "horrific conditions in the mining industry"
Antonym: inoffensive (indirect, via offensive)
- hideous, repulsive - so extremely ugly as to be terrifying; "a hideous scar"; "a repulsive mask"
Antonym: beautiful (indirect, via ugly)