What is wet wing in aeronautical terms?

A wet wing is an aerospace engineering technique where an aircraft’s wing structure is sealed and used as a fuel tank. By eliminating the need for fuel bladders, aircraft can weigh less and offer improved performance. Wet wings are common among civilian designs, from airliners to small general aviation aircraft. Because tanks are an integral part of the structure, they cannot be removed, and require access panels for routine maintenance and visual inspections.