A brand of jockstrap from the manufacturer "Jock Sock" featuring a pouch for supporting the male genitals that is sewn directly into the waistband, obviating the need for straps.
Oscar-winner Yul Brynner was the face of Jock Sock in "Yul Brynner for Jock Sock" advertisements carried in comic books and men's magazines in the late 1960s.
A Spock Jock is an uber nerd, they are typically rational and intelligent. Their favourite novels and films are about space and their T-Shirts have sayings on them or retro gaming consoles.
Friend 1: I don't know how to describe Natalie, she's like nerdy to the power of awesome.