A geometer; a mathematician specializing in the study of geometry.(noun)
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Use "geometrician" in a sentence
"A characteristic note of his scientific speculations is his fondness for considering social phenomena from a mathematical point of view, so that he was called the geometrician of economy."
"Be this as it may, this character in the comedy is called the "geometrician," and does his best to make himself unbearable to those who are toiling with pickaxe and shovel."
"What they were looking at was a dazzling-and, to Bowman, eye-wrenching - exhibition of shapes and colors, as if a mad geometrician was displaying his wares."