The ultrasound report says "cbd is prominent,measuring approx 8.2 mm in size." what does this mean?

The common bile duct: drains bile from the liver and gallbladder into the duodenum. The upper limit of normal for your age would be 5-6mm diameter. The duct can dilate if it is obstructed by a stone, mass, or stricture. The duct can also be passively dilated following gallbladder removal or other biliary surgery/procedures, in which case it is not due to obstruction but is the "new normal" for you. Talk to your doc.