The term 'opposite of svelte' can be answered with the crossword solution 'STOUT', which is a five-letter word. STOUT is an adjective that describes someone or something that is large, heavy, and solid. It is often used to describe people who are overweight, but it can also be used to describe objects such as furniture or buildings. In comparison to svelte, which means slender and graceful, STOUT implies a lack of grace and a more substantial size.