The realm, domain, or position of authority held by a chef, or the collective world and culture of professional chefs.
From 'chef' (from French chef meaning 'head') plus the English suffix '-dom' (meaning realm or domain, as in kingdom, dukedom). This was formed in English following the pattern of words describing a particular sphere of authority or expertise.
The suffix '-dom' has been adding sovereignty to English words since Anglo-Saxon times—it transforms any noun into a universe of its own, whether that's boredom, stardom, or chefdom.
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