Source : Webster's Revised Unabridged Dictionary (1913)

K \K\, (k[=a]),
   the eleventh letter of the English alphabet, is nonvocal
   consonant. The form and sound of the letter K are from the
   Latin, which used the letter but little except in the early
   period of the language. It came into the Latin from the
   Greek, which received it from a Ph[oe]nician source, the
   ultimate origin probably being Egyptian. Etymologically K is
   most nearly related to c, g, h (which see).

   Note: In many words of one syllable k is used after c, as in
         crack, check, deck, being necessary to exhibit a
         correct pronunciation in the derivatives, cracked,
         checked, decked, cracking; since without it, c, before
         the vowels e and i, would be sounded like s. Formerly,
         k was added to c in certain words of Latin origin, as
         in musick, publick, republick; but now it is omitted.

   Note: See Guide to Pronunciation, [sect][sect] 240, 178, 179,
         185.

Source : WordNet®

K
     n 1: the basic unit of thermodynamic temperature adopted under
          the Systeme International d'Unites [syn: {kelvin}]
     2: a light soft silver-white metallic element of the alkali
        metal group; oxidizes rapidly in air and reacts violently
        with water; is abundant in nature in combined forms
        occurring in sea water and in carnallite and kainite and
        sylvite [syn: {potassium}, {atomic number 19}]
     3: the cardinal number that is the product of 10 and 100 [syn:
        {thousand}, {one thousand}, {1000}, {M}, {chiliad}, {G}, {grand},
         {thou}, {yard}]
     4: a unit of information equal to one thousand (1024) bytes
        [syn: {kilobyte}, {KB}]
     5: the 11th letter of the Roman alphabet
     6: street names for ketamine [syn: {jet}, {super acid}, {special
        K}, {honey oil}, {green}, {cat valium}, {super C}]

Source : Free On-Line Dictionary of Computing

K
     
         {kilo-}, a {kilobyte}.  Used both as a spoken word and
        a written suffix, like {meg} and {gig} for {megabyte} and
        {gigabyte}.
     
        See {prefix}.
     
        [{Jargon File}]
     
        (1995-09-29)