The term 'quantity of contraband' can be represented by the word 'kilo', which is a four-letter word. A kilo is a unit of measurement that is equal to 1, 000 grams or 2.2 pounds. It is commonly used to measure the weight of drugs and other illegal substances. Therefore, when referring to a quantity of contraband, it is likely that the term 'kilo' is being used to indicate the amount of the substance in question.