Pronunciation: ( jā),[key] —n., —pl.J's or Js, j's or js. 1. the tenth letter of the English alphabet, a consonant.
2. any spoken sound represented by the letter J or j, as in just, major, or rajah. 3. something having the shape of a J. 4. a written or printed representation of the letter J or j. 5. a device, as a printer's type, for reproducing the letter J or j.
2. Also,jPhysics.joule; joules.
—Symbol. 1. the tenth in order or in a series, or, when I is omitted, the ninth.
2. (sometimes l.c.) the medieval Roman numeral for 1. Cf. Roman numerals.
—Symbol. 1. Math.a unit vector on the y-axis of a coordinate system.
2. Engin.the imaginary number &minus1sqrootover;.