Silver-gilt or gilded/gilt silver, sometimes known in American English by the French term vermeil, is silver (either pure or sterling) which has been gilded with gold. Most large objects made in goldsmithing that appear to be gold are actually silver-gilt; for example most sporting trophies (including medals such as the gold medals awarded in all Olympic Games after 1912) and many crown jewels are silver-gilt objects.
Apart from the raw materials being much less expensive to acquire than solid gold of any karat, large silver-gilt objects are also noticeably lighter if lifted, as well as more durable (gold is much heavier than even lead and is easily scratched and bent). For objects that have intricate detail like monstrances, gilding greatly reduces the need for cleaning and polishing, and so reduces the risk of damage. Ungilded silver would suffer oxidation and need frequent polishing; gold does not oxidize at all. The "gold" threads used in embroidered goldwork are normally also silver-gilt.