Original sin: Innate depravity (=corruption, i.e. moral deterioration) common to all human beings in consequence of the fall (=Adam's sin and its results). — the Concise Oxford Dictionary, 1964 edition.
Interesting that the fall is defined in the Bible as Adam's sin, though the Original Serpent and the woman (later named Eve) had sinned first, as noted by how the punishments were meted out in the latter half of Genesis 3.