A Shriner is a member of a United States men’s club linked to Freemasonry: you are normally already a Mason of high rank before you join. Shriners are famous for charity work with children — they run a well-known group of hospitals — and for a travelling circus, parades, and a red felt hat called a fez. In ordinary American talk, “the Shriners” means that parade-and-hospital group, not priests at a holy shrine. Though actually, the club’s old full name does talk about a shrine, which is why the members are Shriners. You rarely need the word outside US news, films, or someone mentioning those hospitals.