Final answer:
The large fold of the peritoneum described is known as the omentum, which extends from the stomach and is draped over the small intestine and transverse colon.
Step-by-step explanation:
The large fold of the peritoneum that extends from the stomach and passes anteriorly over the colon and small intestine is known as the omentum. Specifically, this apron-like structure is called the greater omentum. It is a significant site of fat deposition in individuals who are overweight and it lies superficial to the small intestine and transverse colon. The visceral peritoneum, which the omentum is a part of, contains other major folds that help to secure the abdominal organs to the posterior abdominal wall. These folds also encase blood vessels, lymphatic vessels, and nerves to provide support and innervation to the organs.