The Collaborative International Dictionary of English v.0.48:

Dim \Dim\, a. [Compar. Dimmer; superl. Dimmest.] [AS. dim;
   akin to OFries. dim, Icel. dimmr: cf. MHG. timmer, timber; of
   uncertain origin.]
   1. Not bright or distinct; wanting luminousness or clearness;
      obscure in luster or sound; dusky; darkish; obscure;
      indistinct; overcast; tarnished.
      [1913 Webster]

            The dim magnificence of poetry.       --Whewell.
      [1913 Webster]

            How is the gold become dim!           --Lam. iv. 1.
      [1913 Webster]

            I never saw
            The heavens so dim by day.            --Shak.
      [1913 Webster]

            Three sleepless nights I passed in sounding on,
            Through words and things, a dim and perilous way.
                                                  --Wordsworth.
      [1913 Webster]

   2. Of obscure vision; not seeing clearly; hence, dull of
      apprehension; of weak perception; obtuse.
      [1913 Webster]

            Mine eye also is dim by reason of sorrow. --Job
                                                  xvii. 7.
      [1913 Webster]

            The understanding is dim.             --Rogers.
      [1913 Webster]

   Note: Obvious compounds: dim-eyed; dim-sighted, etc.

   Syn: Obscure; dusky; dark; mysterious; imperfect; dull;
        sullied; tarnished.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dim \Dim\, v. t. [imp. & p. p. Dimmed; p. pr. & vb. n.
   Dimming.]
   1. To render dim, obscure, or dark; to make less bright or
      distinct; to take away the luster of; to darken; to dull;
      to obscure; to eclipse.
      [1913 Webster]

            A king among his courtiers, who dims all his
            attendants.                           --Dryden.
      [1913 Webster]

            Now set the sun, and twilight dimmed the ways.
                                                  --Cowper.
      [1913 Webster]

   2. To deprive of distinct vision; to hinder from seeing
      clearly, either by dazzling or clouding the eyes; to
      darken the senses or understanding of.
      [1913 Webster]

            Her starry eyes were dimmed with streaming tears.
                                                  --C. Pitt.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dim \Dim\, v. i.
   To grow dim. --J. C. Shairp.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dim
    adj 1: lacking in light; not bright or harsh; "a dim light
           beside the bed"; "subdued lights and soft music" [syn:
           dim, subdued]
    2: lacking clarity or distinctness; "a dim figure in the
       distance"; "only a faint recollection"; "shadowy figures in
       the gloom"; "saw a vague outline of a building through the
       fog"; "a few wispy memories of childhood" [syn: dim,
       faint, shadowy, vague, wispy]
    3: made dim or less bright; "the dimmed houselights brought a
       hush of anticipation"; "dimmed headlights"; "we like dimmed
       lights when we have dinner" [syn: dimmed, dim] [ant:
       bright, undimmed]
    4: offering little or no hope; "the future looked black";
       "prospects were bleak"; "Life in the Aran Islands has always
       been bleak and difficult"- J.M.Synge; "took a dim view of
       things" [syn: black, bleak, dim]
    5: slow to learn or understand; lacking intellectual acuity; "so
       dense he never understands anything I say to him"; "never met
       anyone quite so dim"; "although dull at classical learning,
       at mathematics he was uncommonly quick"- Thackeray; "dumb
       officials make some really dumb decisions"; "he was either
       normally stupid or being deliberately obtuse"; "worked with
       the slow students" [syn: dense, dim, dull, dumb,
       obtuse, slow]
    v 1: switch (a car's headlights) from a higher to a lower beam
         [syn: dim, dip]
    2: become dim or lusterless; "the lights dimmed and the curtain
       rose"
    3: make dim or lusterless; "Time had dimmed the silver"
    4: make dim by comparison or conceal [syn: blind, dim]
    5: become vague or indistinct; "The distinction between the two
       theories blurred" [syn: blur, dim, slur] [ant:
       focalise, focalize, focus]

Moby Thesaurus II by Grady Ward, 1.0:

252 Moby Thesaurus words for "dim":
   achromatic, achromatize, achromic, amorphous, anemic, ashen, ashy,
   banausic, bandage, barely audible, becloud, bedarken, bedazzle,
   bedim, befog, begloom, benight, black, black out, blacken, blah,
   blanch, bleach, blear, blear-eyed, bleared, bleary, bleary-eyed,
   bled white, blind, blind the eyes, blindfold, block the light,
   bloodless, blot out, blunt, blunt-witted, blur, blurred, blurry,
   brown, cadaverous, caliginous, cast a shadow, chloranemic,
   clear as mud, cloud, cloud over, cloudy, colorless, confused, dark,
   dark-colored, darken, darken over, darkish, darkle, darksome, daze,
   dazzle, dead, deadly pale, deathly pale, decolor, decolorize,
   decrescendo, defocus, deprive of sight, dim out, dim-eyed,
   dim-sighted, dim-witted, dimmed, dimmish, dimpsy, dingy, discolor,
   discolored, distant, dopey, drain, drain of color, dreary, dull,
   dull of mind, dull-headed, dull-pated, dull-sighted, dull-witted,
   dusk, dusky, eclipse, encloud, encompass with shadow, etiolate,
   etiolated, excecate, exsanguinated, exsanguine, exsanguineous,
   fade, faded, faint, faint-voiced, fallow, fat-witted, feeble,
   feeble-eyed, film, filmy, filmy-eyed, flat, fog, foggy, fume,
   fuzzy, gentle, ghastly, glare, gloam, gloom, gloomy, gouge,
   gravel-blind, gray, gross-headed, grow dark, grow dim, haggard,
   half-blind, half-heard, half-seen, half-visible, haze, hazy, heavy,
   hebetudinous, hoodwink, hueless, humdrum, hypochromic, ill-defined,
   inconspicuous, indefinite, indeterminate, indistinct,
   indistinguishable, lackluster, leaden, livid, lose resolution, low,
   low-profile, lower, lurid, lusterless, make blind, mat, mealy,
   merely glimpsed, mist, misty, mole-eyed, monotone, monotonous,
   muddy, murk, murksome, murky, murmured, muted, nebulous, neutral,
   obfuscate, obnubilate, obscure, obtuse, obumbrate, occult,
   occultate, opaque, out of focus, overcast, overcloud, overshadow,
   pale, pale as death, pale-faced, pallid, pasty, pedestrian,
   peroxide, pianissimo, piano, poky, purblind, sallow, sand-blind,
   scarcely heard, semidark, semivisible, shade, shadow, shadowy,
   shapeless, sickly, slow, slow-witted, sluggish, snow-blind, soft,
   soft-sounding, soft-voiced, soften, somber, stodgy, strike blind,
   subaudible, subdued, subfusc, tallow-faced, tarnish, tenebrous,
   thick-brained, thick-headed, thick-pated, thick-witted,
   thickskulled, tone down, toneless, transcendent, uncertain,
   unclear, uncolored, undefined, undetermined, unilluminated,
   unplain, unrecognizable, vague, wan, wash out, washed-out, waxen,
   weak, weak-eyed, weak-voiced, whey-faced, whispered, white, whiten,
   wooden



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

DIM statement
DIM

    (From "dimension") A keyword in most versions
   of the BASIC programming language that declares the size of
   an array.  E.g.

   	DIM A(100)

   declares a one-dimensional array with 101 numeric elements
   (including A(0)).

   Visual Basic uses the DIM (or "Dim") statement for any
   variable declaration, even scalars, e.g.

   Dim DepartmentNumber As Integer

   which declares a single (scalar) variable of type Integer.

   (1999-03-26)