acronym stands for Single White Female. is also used to refer to a girl who develops an obsession with another girl (whether out of jealousy or crush) and begins to act like her, either knowingly or unknowingly. sometimes referred to as stalking
, but more of a thin line between love and hate.
can be used as a verb as well.
"wow, she found your livejournal and started quoting it as her own words in her blog? she totally SWF'ed you!"