the letter is a late modification of Roman -i-, originally a scribal creation in continental M.L. to distinguish small -i- in cursive writing from the strokes of other letters, especially in the final positions of words. But in Eng., -y- was used for this, and -j- was introduced c.1600-1640 to take up the consonantal sound that had evolved from -i- since L.L. times. This usage first was attested in Sp., where it was in place before 1600. Eng. dictionaries continued to lump together words beginning in -i- and -j- until 19c.
(also jay or jay smoke or J smoke) A marijuana cigarette; joint
[1960s+ Narcotics; fr the J of Mary Jane, ''marijuana,'' or the j of joint]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
j in Technology
A derivative and redesign of APL with added features and control structures. J is purely functional with lexical scope and more conventional control structures, plus several new concepts such as function rank and function arrays. J was designed and developed by Kennneth E. Iverson and Roger Hui . J uses only the ASCII character set but has a spelling scheme that retains the advantages of APL's special alphabet. J is a conventional procedural programming language but can be used as a purely functional language. Version 4.1 for MS-DOS, Sun, Mac, Archimedes. Source available in C from Iverson Software, +1 (416) 925 6096. Version 6 package from ISI includes an interpreter and tutorial. Ported to DEC, NeXT, SGI, Sun-3, Sun-4, Vax, RS/6000, MIPS, Macintosh, Acorn Archimedes, IBM PC, Atari, 3b1, Amiga. (ftp://watserv1.waterloo.edu/languages/apl/j). J-mode GNU Emacs macros available by (ftp://think.com/pub/j/gmacs/j-interaction-mode.el). ["APL\?", Roger K.W. Hui et al, APL90 Conf Proc, Quote Quad 20(4):192-200]. (1992-10-31)