Meaning 1: A small, crudely built dwelling
* Antonyms: Mansion, palace, manor, villa, chateau, estate, luxury home, high-rise, skyscraper.
Meaning 2: A type of folk song, often associated with sailors
* Antonyms: Symphony, opera, concerto, sonata, classical music, pop music, rock music, electronic music, jazz.
Meaning 3: A small shed or hut used for storage or work
* Antonyms: Warehouse, factory, office building, skyscraper, mansion.
The best antonym for "shanty" will depend on the specific context in which it's used.