(n.) the topmost crown of prongs in a stag’s antlers
The shapes formed by a stag’s antlers might seem somewhat random to us, but there’s method in the madness.
In fact, so regular are some of the shapes that stags’ horns form that different parts of them have been given their own names—including the uppermost ‘crown’ of prongs, furthest from the stag’s head, which is called the surroyal.
Like most of these cervine words, surroyal is an old hunting term. It’s been in use in English since the late Middle English period, suggesting it was likely borrowed from French in the fourteenth century, when the vocabulary of all manner of country pursuits was greatly expanded by England’s ruling Norman classes.
Knowing that this is a French word, the initial ‘sur–’ here probably makes a little more sense: sur means ‘above’ or ‘on top of’ in French (and as such has its origins in the Latin super, which implied much the same thing). As a word forming element, it’s found at the opening of all kinds of different words bearing some sense of topping, beating, overdoing, or coming ahead of something—including such obvious examples as surmount, surfeit and surpass, alongside some less familiar ones like surclouded (obscured from above), surflux (an overflowing), surrebound (to echo into infinity), and surburdened (burdened with a burden atop a burden you already had).
This is also, incidentally, the same ‘sur–’ you’ll find in surname (in the sense that a surname is an additional patriarchal name added alongside your given name), as well as surreal (as in ‘beyond real’), surcingle (a strap that is passed around a horse’s belly), and even sirloin (the cut of meat that comes from above a cow’s loin).
Keep sirloin in mind, actually, because the stag’s surroyal is quite literally the crown of prongs found above a lower growth of prongs, which is itself known as the royal. Beneath that is the lowest of the three layers of prongs, which is simply known as the brow, or browpoint.