say it: HID-ee-uhs
hideous is an adjective meaning "grossly offensive to decency or morality; causing horror". It carries 2 recorded senses.
grossly offensive to decency or morality; causing horror
“subjected to outrageous cruelty”
“a hideous pattern of injustice”
“horrific conditions in the mining industry”
so extremely ugly as to be terrifying
“a hideous scar”
“a repulsive mask”
Definitions, synonyms and semantic relations for hideous come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.