[1] : The Collaborative International Dictionary of English v.0.48

j \j\ j=a.
   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.
   1913 webster

   note: in medical prescriptions j is still used in place of i
         at the end of a number, as a roman numeral; as, vj,
         xij. j is etymologically most closely related to i, y,
         g; as in jot, iota; jest, gesture; join, jugular, yoke.
         see i. 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, sectsect 179,
         211, 239.
         1913 webster
see also:
i 

[2] : WordNet (r) 2.0

j
     n 1: a unit of electrical energy equal to the work done when a
          current of one ampere passes through a resistance of one
          ohm for one second syn: joule, watt second
     2: the 10th letter of the roman alphabet
see also:
joule watt second 

[3] : The Free On-line Dictionary of Computing (27 SEP 03)

j
     
        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
        204:192-200.
     
        1992-10-31
     
     
see also:
apl purely functional lexical scope function rank function array ascii 
purely functional ms-dos iverson software dec next 
sgi sun-3 sun-4 vax rs/6000 
mips macintosh acorn archimedes ibm pc atari 
3b1 amiga lt;ftp://watserv1.waterloo.edu/languages/apl/jgt; gnu emacs lt;ftp://think.com/pub/j/gmacs/j-interaction-mode.elgt; 

A Portrait Of J >> A Words
A Portrait Of J, definition of term: A Portrait Of J
a+portrait+of+j_pag1.html