Since Pokorny, traditionally derived from a Proto-Indo-European *dʰH- (“to disappear”), and connected with Latin affatim, fatīscō, fatīgō, fessus, as well as Old Irish dedaid (“to melt away; to grow weary”), Old Norse dási (“slow”), and English daze. However, De Vaan rejects this etymology, considering the forms and semantics as too vague, and leaves the origin open.