ineffable
adj.adj. too great or beautiful to be described with words. You use this when a feeling is so strong that you cannot explain it exactly.
adj. too great, sacred, or intense to be expressed or described in words. Frequently used in literary or theological contexts to denote qualities beyond human comprehension.
The mountain sunset fills her with ineffable joy.
After the long journey, the travelers felt an ineffable sense of relief as they finally crossed the border.
The poet spent years trying to capture the ineffable beauty of the arctic landscape, yet eventually admitted that language alone could never match the physical experience.
From Middle French ineffable (modern French ineffable), from Latin ineffābilis, from in- (“not”) + effor (“utter”) + -bilis (“-able”).