inenarrable

Ineffable, "inenarrable," "indescribable" - English has quite a few words for expressing that which can't be expressed. The prefix in-, meaning "not," teamed up with Latin enarrare ("to explain in detail") to give us "inenarrable," and the same prefix joined with Latin effabilis ("capable of being expressed") to create "ineffable." English speakers have used "ineffable" since the 14th century, and "inenarrable" made its way into the language from French in the 15th century. "Indescribable" was a late arrival, relatively speaking - it has only been with us since the 18th century.