镀金 literally means 'to gold-plate', but it's more commonly used figuratively to describe getting a superficial prestigious credential — like studying abroad or earning a degree from a famous school — to enhance one's social image or resume. It's a separable verb (离合词): you can insert a measure word or adjective between 镀 and 金, e.g., 镀了一层金 ('plated with a layer of gold'). The figurative sense carries a mild negative connotation of surface-level improvement without real substance.