Short for "Scrum-half", which is a Rugby union position. The scrummie's job is to choose how and where the ball will be played in each phase of play and take control of the ball from set pieces (lineouts and scrums), rucks and mauls. Comparable to the quarterback in American football.
Scrombie, noun: A person only talking about scrum methodology and completely unaware of his or her surroundings and entirely absorbed in their agile environment, a mixture between scrum and zombie.
This is acombination of "Scro", (a playoff of the words brother and scrotum) and "homey" short for homeboy, someone you grew up with, someone you trust and admire.
My big brother and I are only two years apart in age, he is my older sibling, but we are tight and his nick name of bro has evolved throughout the years to scro, and now scromie. Basically, I am referring to my bro as a ball sack which also is my Homeboy!