inexpressible

inexpressible /ˌɪnɪkˈsprɛsəbəl/ adjective
inexpressible
/ˌɪnɪkˈsprɛsəbəl/
adjective
Britannica Dictionary definition of INEXPRESSIBLE
somewhat formal
: too strong or great to be expressed or described

— inexpressibly

/ˌɪnɪkˈsprɛsəbli/ adverb