Zaftig refers to someone who is plump or curvy in a pleasing or attractive way. The antonyms for zaftig include terms that describe people who are skinny or underweight. Some of the most commonly used antonyms for zaftig include words like scrawny, skinny, lanky, bony, and gaunt. However, these words have negative connotations and are often considered offensive. Instead, it is better to use more neutral terms like slender, lean, wiry, or athletic when referring to someone who is not zaftig. In any case, it is important to use respectful and positive language when talking about someone's body type.