Dictionary of Business Terms: sack
sack
discharge, terminate, fire (an employee); the employee "gets the sack," originally meaning that he picked up his sack of tools and moved on.
Dictionary of Marketing Terms: sack
sack
canvas mail bag containing one or more packages of mail for a common destination. Sacks vary in size and capacity. The most common sack sizes are a #2, which holds 70 pounds, and a #3, which holds 45 pounds. In practice, some amount less than the maximum capacity is placed into the sack.