The feeling gained and expression used when winning a big bet and/or the description of someone betting on an '"outsider". i.e "Chasing the scomp"
Bobby: "I cannot believe you are putting a tenner on the 33/1 shot, you are really chasing the scomp there, James"
James: "What a scomp! i am scomping all over the bookies!"
Bobby: "Boy! That was one hefty scomp! you are the scomp king"