infallible

/ɪnˈfæləbəl/
adjective
  1. Incapable of making mistakes or being wrong; always accurate or reliable.
    • This test is not infallible, so a negative result does not guarantee you are healthy.
    • No leader is infallible; everyone makes errors sometimes.
    • My grandmother's recipe is infallible — it always turns out perfect.
Antonyms
What does "infallible" mean? | whatsthatwordmean | whatsthatwordmean