The inherent ability to attract females to your location, merely through your attractiveness, cleverness, and most of all, swag.
Chris- "Wow, yesterday none of those girls were sitting next to Tommy and now he is knee deep in ham wallets."
Brosef Stalin- "Yeah, he's got some strong swagnetism."
Swagnacious is the ultimate word used only by people who are brave enough to use it. It is the next level up from the common term used 'swag'. This word cant be reached by basic, boring people. It is used to describe something so utterly amazing and cool which the word 'swag' would just not justify.
Speaker 1: Oh look at Aimee and Katie they are so Swagnacious!
Speaker 2: I know! They are amazing.