There are several antonyms for the phrase "gotten taller." These include "gotten shorter," "shrunk," "dwindled," "diminished," "declined," "decreased," and "reduced." These words indicate a decrease in height or stature, opposite to "gotten taller." A person may "shrink" due to age or illness while "dwindling" could suggest a decrease in size when referring to an object. Similarly, "declined" and "reduced" can also refer to the decrease in height or stature of an individual, but mostly related to physiological growth. Hence, these antonyms can be useful in describing a decrease in height, size or stature.