Final answer:
The term for the main cable in a suspension structure is a suspension cable, which is integral for weight distribution and defining the structure's curve.
Step-by-step explanation:
In civil engineering, the term for the main cable used in a suspension structure, such as a suspension bridge, to anchor a set of secondary cables is known as a suspension cable. Suspension cables are critical for the structural integrity of suspension bridges and similar constructs. By distributing the weight evenly and sustaining immense tension, these cables define the characteristic curve of the structure, just like the iconic Golden Gate Bridge. They must be able to withstand substantial loads, as exemplified when calculating the stretching of a long cable in a ski resort's gondola system, where the maximum tension and dimensions of the cable are considered to ensure safety and functionality.