You searched for: “vertiginousness
vertiginousness (s) (noun), (usually no plural)
1. A spinning of or a rotary activity: "Sometimes wind currents are vertiginousness in their movements."
2. A feeling of giddiness or a sense of dizziness: "People who have feeling of vertiginousness must be careful or they could pass out or stumble and injure themselves."

"A high walkway over a canyon can cause serious vertiginousness for some people; especially, when it is wobbling, or moving back and forth, or shaking."