There are plenty of synonyms for the phrase "in one's dotage," all of which convey a similar meaning. Some options include "senile," "demented," "feeble-minded," "gaga," "confused," and "forgetful." Each of these terms describes a person who is experiencing a decline in cognitive function as they age, often resulting in memory loss, confusion, and a general sense of mental confusion. While these terms may seem harsh or negative, it's important to remember that many seniors still lead happy and fulfilling lives well into their later years!