The antonym of 'beautiful' is 'ugly'. An antonym is a word that has the opposite meaning of another word. Where 'beautiful' describes something that is pleasing to the senses or has charm and grace, 'ugly' denotes the opposite, often describing something that is unpleasant to look at. The other options, such as 'attractive', 'pretty', and 'gorgeous', are all synonyms or words with similar meanings to 'beautiful'.
