There are several synonyms for the phrase "wear down," which typically means to diminish or tire out over time. Some similar expressions include "exhaust," "weaken," "tire," "expend," "flatten," "erode," "deplete," and "sap." Each of these terms describes a gradual process of removal or depletion, often resulting in decreased energy or effectiveness. Whether used to describe physical or mental weariness, these words convey a sense of gradual loss or depletion that can signal the need for rest, recovery, or renewal. Choosing the right synonym for "wear down" will depend on the context and desired emotional impact of the sentence or phrase.