Virility refers to any of a wide range of masculine characteristics viewed positively. It isn't applicable to women or to negative characteristics. The Oxford English Dictionary (OED1) says virile's "marked by strength or force." Virility's commonly associated with vigour, health, sturdiness, and constitution, especially in the fathering of children. In this last sense, virility's to men as fertility's to women. OED1 also notes an obsolete use of virile in this sense for a "nubile" young woman… (More on Virility)