The word "ex pound" refers to something or someone who has been released or removed from captivity in a pound or animal shelter. As an antonym, the opposite of ex pound would be "in pound," which means that the individual or animal is currently being held or detained in a pound. Another antonym could be "held captive," which implies that the person or animal is being held against their will in a confined space. "Detained," "incarcerated," and "imprisoned" are other possible antonyms of ex pound, all of which essentially indicate that someone or something is being held in confinement or captivity.