Separated by a diameter, on exactly the opposite side. Frequently used in the phrase diametrically opposed meaning absolutely in opposition.(adverb)
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Use "diametrically" in a sentence
"The gorgeousness is in the imagery not in the language; the words are weak while the sense, as in the classical Scandinavian books, is strong; and here the Arabic differs diametrically from the florid exuberance and turgid amplifications of the Persian story-teller, which sound so hollow and unreal by the side of a chaster model."
"But such a libertarianism would not be the libertarianism we know and would find most of what goes by the name diametrically opposed to its essential spirit and goals."
"The two statements quoted above contain diametrically opposite conceptions of this country, its future and its destiny."