The antonyms for the word "puffed out" are compressed, flat, deflated, and shriveled. These words describe the opposite condition of being swollen or inflated, which is what "puffed out" means. So, someone who is not puffed out might look thin, shrunken, or collapsed. Similarly, an object that is not puffed out might be compact, squished, or even completely flat. These antonyms can be useful when describing a particular state or condition of something, and can enhance the precision and accuracy of your writing by providing more specific information to your readers.