A slut, who most likely has a boyfriend, who goes around strategically flirting with guys on the down low, thus planting seeds in the case that shit goes bad in the current relationship. They may occasionally have a random hookup which always ends with blue balls. Girls who take part are usually a 7+ out of 10. Traits: deceptive, misleading, lots of excuses, generally loose.
"Man, I was proper blue balled last night, turns out she was just a seedplanter."