Wiktionary
cornerpiece
n. Part of an object that fits at its corner.
Usage examples of "cornerpiece".
A terminal with several screens and an entertainment selector panel, black and silver, with aluminum controls, formed a cornerpiece between a black-upholstered recliner and a glass-sided, slender-legged desk.
No need to dwell on the legendary beauty of the cornerpieces, the acme of art, wherein one can distinctly discern each of the four evangelists in turn presenting to each of the four masters his evangelical symbol, a bogoak sceptre, a North American puma (a far nobler king of beasts than the British article, be it said in passing), a Kerry calf and a golden eagle from Carrantuohill.