DictionaryuntoldImmeasurably great
adjective

untold

Too great in amount or extent to measure or describe.

Untold numbers of birds form a dense flock stretching into the distance.

An immense, densely packed flock of birds stretches from a few distinct foreground birds into innumerable tiny silhouettes receding across the distance, illustrating the 'too great to count' branch of the frozen meaning.
Etymology

Tell once commonly meant count. Untold quantities are uncounted and, by extension, too numerous or extensive to reckon.

In context

Veil of Mystery4:50
Below the bustling streets, an untold number of places [music] lie dormant, sealed by centuries of construction, buried by the relentless accumulation of time.
Forbidden Artifacts That Shatter Official History

More examples

  • The flood causes untold damage to homes and businesses.
  • She spends untold hours caring for injured animals.
  • The discovery promises untold benefits for future patients.

Forms

untold

Similar words

innumerable
Emphasizes numbers too large to count, rather than overall extent.
immeasurable
Emphasizes greatness beyond measurement, especially of feelings or effects.
incalculable
Emphasizes amounts or consequences too great to calculate.