You use ineffable to say that something is so great or extreme that it cannot be described in words. the ineffable sadness of many of the portraits. = indescribable + ineffably in·ef·fably his ineffably powerful brain. too great to be described in words (ineffabilis, from effari )
A term used by Dr Raymond Moody in his book Life After Life (1975)to represent the inability of NDE survivors to describe their experiences It signifies the inadequacy of language or words to depict what was seen and felt during the NDE particularly with regards to the light The term has also been used to signify that the sacredness of the experience exceeds any ability to express it