A more thorough explanation:

Definition: Unerring (n-uh-ring or n-er-ing) is an adjective that means incapable of error or infallible.

• The unerring accuracy of the GPS system helped us navigate through the unfamiliar city.
• Her unerring intuition always led her to make the right decisions.
• The archer's unerring aim hit the bullseye every time.

The examples illustrate the definition of unerring by showing situations where there is no possibility of error. In the first example, the GPS system is described as unerring because it is always accurate and never makes mistakes. In the second example, the person's intuition is described as unerring because it always leads to the right decision. In the third example, the archer's aim is described as unerring because it always hits the target with precision.