Gross-weight deduction is a term used in the shipping industry to refer to the process of subtracting the weight of packaging materials from the total weight of a shipment. This process is also known as TARE and tret, two words which are commonly used in crossword puzzles. TARE is the weight of the packaging material, while tret is the weight of the goods themselves. By subtracting the TARE from the gross weight, the net weight of the shipment can be determined.