“Spirituality” is a word for which there is no counterpart in classical Hebrew. Ruhaniut, the word in modern Hebrew, is itself a translation of the English term. Ruhaniut is derived from ruah, which means breath or wind, and, derivately, spirit. Its first occurrence is at the very beginning of the Torah:

By Maimonides' time ruah had developed a wide range of uses, including, very importantly, ruah ha-qodesh, the spirit of holiness (or, as more usually translated, “the holy spirit”), and, very differently, ruah tumah, the spirit of ritual impurity (often used to mean demons). The one meaning the word does not have in classical or even medieval Hebrew is “spiritual” in the sense of “spiritual life.” The closest one can come to this expression, I think, in classical Judaism is “holy life.”