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Webster 1913 Edition
J
J
(jā)
. J is the tenth letter of the English alphabet. It is a later variant form of the Roman letter I, used to express a consonantal sound, that is, originally, the sound of English y in yet. The forms J and I have, until a recent time, been classed together, and they have been used interchangeably.
J is a compound vocal consonant, nearly equivalent in sound to dzh. It is exactly the same as g in gem. See Guide to Pronunciation , §§ 179, 211, 239.