Source : Webster's Revised Unabridged Dictionary (1913)

Kern \Kern\, v. t. [imp. & p. p. {Kerned}; p. pr. & vb. n.
   {Kerning}. ] (Type Founding)
   To form with a kern. See 2d {Kern}.

Source : Free On-Line Dictionary of Computing

kerning
     
         The process of reducing the spacing between certain
        pairs of letters to improve their appearance.  When a {font}
        is created, each {character} is given a width that includes
        some space around it so that the letters don't run into each
        other when displayed or printed.  This can be thought of as an
        invisible box around each character.  Some pairs of characters
        such as A and V, look better if the boxes overlap slightly,
        bringing the characters closer together (but still not
        touching).
     
        See also {tracking}, {leading}.
     
        (1996-06-07)