The term 'vigorish' (which is essentially always shortened to 'vig'), comes from the Yiddish term vyigrysh, which means "profit or winnings."
The term is used in many settings, especially financial and gaming settings, to describe the cut taken by an intermediary. An inter-dealer broker who charges a fee of 1/2 of 1% for arranging a swap transaction would be described as "taking a 50 basis point vig".
The term is also used to describe the fee paid at the door to enter an illegal gambling hall, or the interest paid to a loan shark, or the service fee paid to a software company or ECN in exchange for use of its network.