immense
Extremely large in size, amount, or degree.
Immense means extremely large or vast beyond the ordinary. When something is immense, it's so big that it can feel hard to grasp or measure. The Pacific Ocean is immense, stretching thousands of miles in every direction. The universe is immense, containing billions of galaxies. An immense crowd might fill a stadium so completely that you can barely see the field.
The word works for size you can see, like an immense building that towers over everything around it, or for amounts and qualities you can't, like the immense relief you feel when you finally find your lost dog. A problem can be immense if it seems overwhelmingly big and complicated. A person might have immense talent, meaning their skill goes far beyond what's typical.
Immense suggests something so large it inspires awe or even makes you feel small by comparison. Standing at the edge of the Grand Canyon, you experience its immense scale: the massive walls of rock drop thousands of feet, and the canyon stretches so far you can't see where it ends. That feeling of being dwarfed by something's sheer magnitude captures what immense really means.