j

J is the tenth letter in the English alphabet. (noun)

An example of j is the first letter in the word Jerusalem.

See j in Webster's New World College Dictionary

or J

noun pl. J's, j's

the tenth letter of the English alphabet: formerly a variant of I, i, in the 17th cent. it became established as a consonant only, as in Julius, originally spelled Iulius
any of the speech sounds that this letter represents, as, in English, the j of joy
a type or impression for j or J
the tenth in a sequence or group
an object shaped like

adjective

noun

Physics the imaginary number

See j in American Heritage Dictionary 4

or J (jā)

noun pl. J's j's or J's also js or Js

The tenth letter of the modern English alphabet.
Any of the speech sounds represented by the letter j.
The tenth in a series.
Something shaped like the letter J.
J The hypothetical traditional source of those portions of the Pentateuch in which God is referred to with the Tetragrammaton rather than as Elohim.

or J

Electricity

The symbol for current density .

abbreviation