The antonyms for the word "light industry" are heavy industry, manufacturing, and heavy machinery. Heavy industry refers to the production of goods and products that require large and complex machinery, such as metalworking, chemical production, and mining. Manufacturing is a broader term that encompasses the production of all types of products, including those that require both heavy and light industry processes. Heavy machinery refers to the machines and equipment used in heavy industry, such as bulldozers, cranes, and excavators. These industries are often more resource-intensive and require more energy, space, and labor than light industry.