1. n. a portion of your mind/brain dedicated to all the best memories of great dreams, fantasies, beautiful women you've seen or fucked, naked ugly whores you've accidentally fucked, or a celebrity nipslip you've seen. A spankodex is most commonly accessed during the masturbatory process. (ALSO spank-o-dex)
After seeing a bikini top slip off at the beach, Adam replied "that's getting filed in the spankodex!"