A Seimen Magnet is someone who attracts STD's at a quicker pace than the rest of those who are sexually active. You can generally recognise these types by their plasterboard makeup, low cut tops, almost invisible skirts despite the weather being a minus degree or several outside. Also see 'slut', 'sure thing' and 'how soon can I get a doctors appointment?' for more information.
by Geektacular February 10, 2015