Alcohol free. For example, a virgin
margarita is one prepared without
tequila or
liqueurs. Usually applied to drinks prepared for
children or
teetotallers that are usually
alcoholic beverages - you won't hear anyone calling a bottle of
7-Up virgin, even though it is also
non-alcoholic.
Also, someone who has never had
sex. In women, this is traditionally associated with having an unbroken
hymen.
Also, anything
pure and unsullied.
Snow with no footprints in it is called virgin snow, for instance.