ultrareliable

/ˌʌltrərɪˈlaɪəbəl/
adjective
  1. Extremely dependable; able to be trusted completely in all situations.
    • The ultrareliable internet connection never dropped during the entire video call.
    • For a camping trip in remote areas, you need an ultrareliable flashlight.
    • Her ultrareliable car has started on the first try every morning for ten years.
Antonyms
What does "ultrareliable" mean? | whatsthatwordmean | whatsthatwordmean