The Collaborative International Dictionary of English v.0.48:

Ken \Ken\, v. i.
   To look around. [Obs.] --Burton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ken \Ken\, n.
   Cognizance; view; especially, reach of sight or knowledge.
   "Beyond his ken." --Longfellow.
   [1913 Webster]

         Above the reach and ken of a mortal apprehension.
                                                  --South.
   [1913 Webster]

         It was relief to quit the ken
         And the inquiring looks of men.          --Trench.
   Kendal green

The Collaborative International Dictionary of English v.0.48:

Ken \Ken\ (k[e^]n), n. [Perh. from kennel.]
   A house; esp., one which is a resort for thieves. [Slang,
   Eng.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ken \Ken\, v. t. [imp. & p. p. Kenned (k[e^]nd); p. pr. & vb.
   n. Kenning.] [OE. kennen to teach, make known, know, AS.
   cennan to make known, proclaim, or rather from the related
   Icel. kenna to know; akin to D. & G. kennen to know, Goth.
   kannjan to make known; orig., a causative corresponding to
   AS. cunnan to know, Goth. kunnan. [root]45. See Can to be
   able, Know.]
   1. To know; to understand; to take cognizance of. [Archaic or
      Scot.]
      [1913 Webster]

   2. To recognize; to descry; to discern. [Archaic or Scot.]
      "We ken them from afar." --Addison
      [1913 Webster]

            'T is he. I ken the manner of his gait. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ken
    n 1: range of what one can know or understand; "beyond my ken"
         [syn: cognizance, ken]
    2: the range of vision; "out of sight of land" [syn: sight,
       ken]

The Free On-line Dictionary of Computing (19 January 2023):

ken

   /ken/ 1. Ken Thompson

   2. A flaming user.  This was originated by the Software
   Support group at Symbolics because the two greatest flamers
   in the user community were both named Ken.

   [Jargon File]


The Jargon File (version 4.4.7, 29 Dec 2003):

ken
 /ken/, n.

    1. [Unix] Ken Thompson, principal inventor of Unix. In the early days he
    used to hand-cut distribution tapes, often with a note that read “Love, ken
    ”. Old-timers still use his first name (sometimes uncapitalized, because
    it's a login name and mail address) in third-person reference; it is widely
    understood (on Usenet, in particular) that without a last name ‘Ken’ refers
    only to Ken Thompson. Similarly, ‘Dennis’ without last name means Dennis
    Ritchie (and he is often known as dmr). See also demigod, Unix.

    2. A flaming user. This was originated by the Software Support group at
    Symbolics because the two greatest flamers in the user community were both
    named Ken.