The veins in your body that become apparent after using/consuming mass qaunties of methamphetamine.
It occurs when your body temperture fluciates between highs and lows, most oftenly leaving you cold and constricts your blood vessel and makes veins in legs, arms, and hands completely visual to the naked eye.
1: "I just finished tweaking, I just loaded the pizzo so fat!"
2:"Yah, I can tell by your spider veins; you look so cold but it's perfect temperture in here."
1:"Ya... I'm amped..."