The Collaborative International Dictionary of English v.0.48:

Miss \Miss\, v. t. [imp. & p. p. Missed (m[i^]st); p. pr. &
   vb. n. Missing.] [AS. missan; akin to D. & G. missen, OHG.
   missan, Icel. missa, Sw. mista, Dan. miste. [root]100. See
   Mis-, pref.]
   1. To fail of hitting, reaching, getting, finding, seeing,
      hearing, etc.; as, to miss the mark one shoots at; to miss
      the train by being late; to miss opportunites of getting
      knowledge; to miss the point or meaning of something said.
      [1913 Webster]

            When a man misses his great end, happiness, he will
            acknowledge he judged not right.      --Locke.
      [1913 Webster]

   2. To omit; to fail to have or to do; to get without; to
      dispense with; -- now seldom applied to persons.
      [1913 Webster]

            She would never miss, one day,
            A walk so fine, a sight so gay.       --Prior.
      [1913 Webster]

            We cannot miss him; he does make our fire,
            Fetch in our wood.                    --Shak.
      [1913 Webster]

   3. To discover the absence or omission of; to feel the want
      of; to mourn the loss of; to want; as, to miss an absent
      loved one. --Shak.
      [1913 Webster]

            Neither missed we anything . . . Nothing was missed
            of all that pertained unto him.       --1 Sam. xxv.
                                                  15, 21.
      [1913 Webster]

            What by me thou hast lost, thou least shalt miss.
                                                  --Milton.
      [1913 Webster]

   To miss stays. (Naut.) See under Stay.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Missing \Miss"ing\, a. [From Miss, v. i.]
   Absent from the place where it was expected to be found;
   lost; lacking; wanting; not present when called or looked
   for.
   [1913 Webster]

         Neither was there aught missing unto them. --1 Sam.
                                                  xxv. 7.
   [1913 Webster]

         For a time caught up to God, as once
         Moses was in the mount, and missing long. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

missing
    adj 1: not able to be found; "missing in action"; "a missing
           person"
    2: nonexistent; "the thumb is absent"; "her appetite was
       lacking" [syn: lacking, absent, missing, wanting]

Moby Thesaurus II by Grady Ward, 1.0:

82 Moby Thesaurus words for "missing":
   absconded, absent, arrested, away, bankrupt in, bare of, bereft of,
   callow, defective, deficient, deleted, denuded of, departed,
   deprived of, destitute of, devoid, devoid of, disappeared,
   embryonic, empty of, existless, extinct, failing, for want of,
   forlorn of, gone, gone away, hypoplastic, immature, in arrear,
   in arrears, in default, in default of, in short supply, in want of,
   inadequate, incomplete, infant, lacking, lost, lost to sight,
   lost to view, minus, needing, negative, no longer present, no more,
   nonattendant, nonexistent, not found, not present, null, omitted,
   out of, out of pocket, out of sight, part, partial, past and gone,
   patchy, scant, scant of, scanty, scrappy, short, short of, shy,
   shy of, sketchy, subtracted, taken away, unblessed with,
   underdeveloped, undeveloped, unexisting, unpossessed of, vacuous,
   vanished, void, void of, wanting, without being



The Free On-line Dictionary of Computing (30 December 2018):

Missing definition
missing

    First, this is an (English language)
   __computing__ dictionary.  It includes lots of terms from
   related fields such as mathematics and electronics, but if
   you're looking for (or want to submit) words from other
   subjects or general English words or other languages, try
   (http://wikipedia.org/), (http://onelook.com/),
   (http://yourdictionary.com/),
   (http://www.dictionarist.com/) or
(http://reference.allrefer.com/).

   If you've already searched the dictionary for a computing term
   and it's not here then please __don't tell me__.  There are,
   and always will be, a great many missing terms, no dictionary
   is ever complete.  I use my limited time to process the
   corrections and definitions people have submitted and to add
   the most frequently requested missing terms (missing.html).

   Try one of the sources mentioned above or
   (http://techweb.com/encyclopedia/),
   (http://whatis.techtarget.com/) or
   (http://google.com/).

   See the Help page (help.html) for more about missing definitions
   and bad cross-references.

   (2014-09-20)