The Collaborative International Dictionary of English v.0.48:

Aloof \A*loof"\, adv. [Pref. a- + loof, fr. D. loef luff, and so
   meaning, as a nautical word, to the windward. See Loof,
   Luff.]
   1. At or from a distance, but within view, or at a small
      distance; apart; away.
      [1913 Webster]

            Our palace stood aloof from streets.  --Dryden.
      [1913 Webster]

   2. Without sympathy; unfavorably.
      [1913 Webster]

            To make the Bible as from the hand of God, and then
            to look at it aloof and with caution, is the worst
            of all impieties.                     --I. Taylor.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Aloof \A*loof"\, prep.
   Away from; clear from. [Obs.]
   [1913 Webster]

         Rivetus . . . would fain work himself aloof these rocks
         and quicksands.                          --Milton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Aloof \A*loof"\, n. (Zool.)
   Same as Alewife.
   [1913 Webster]

WordNet (r) 3.0 (2006):

aloof
    adv 1: in an aloof manner; "the local gentry and professional
           classes had held aloof for the school had accepted their
           sons readily enough"
    adj 1: remote in manner; "stood apart with aloof dignity"; "a
           distant smile"; "he was upstage with strangers" [syn:
           aloof, distant, upstage]

Moby Thesaurus II by Grady Ward, 1.0:

181 Moby Thesaurus words for "aloof":
   Laodicean, Olympian, above, above all that, abovestairs, airward,
   alienated, aloft, alone, antisocial, apart, apathetic, arrogant,
   at a distance, away, backward, bashful, benumbed, blah, blank,
   blase, bored, broken, careless, casual, chilled, chilly, cold,
   comatose, companionless, constrained, cool, desensitized, detached,
   disconnected, discontinuous, discreet, discrete, disdainful,
   disinterested, distant, distantly, dull, exclusive, expressionless,
   forbidding, formal, friendless, frigid, frosty, gapped, guarded,
   haughty, heartless, hebetudinous, heedless, high, high up,
   homeless, hopeless, icy, impassive, impersonal, in a stupor,
   in the air, in the clouds, inaccessible, incoherent, inconsistent,
   incurious, indifferent, insouciant, insular, introverted, isolated,
   kithless, languid, lethargic, listless, lone, lonely, lonesome,
   mindless, modest, nonadherent, nonadhesive, nonchalant,
   noncoherent, noncohesive, numb, numbed, off, offish, on high,
   on stilts, on the peak, on tiptoe, open, over, overhead, passive,
   phlegmatic, pluckless, private, proud, regardless, remote,
   remotely, removed, repressed, reserved, resigned, restrained,
   reticent, retiring, rootless, seclusive, separate, separated,
   shrinking, single-handed, skyward, slack, sluggish, solitary, solo,
   soporific, spiritless, spunkless, standoff, standoffish, stoic,
   stolid, straight up, stupefied, subdued, supercilious, supine,
   suppressed, tenuous, tiptoe, to the zenith, torpid, unabetted,
   unaccompanied, unadhesive, unaffable, unaided, unapproachable,
   unassisted, unattended, unbending, uncaring, uncoherent,
   uncohesive, uncompanionable, unconcerned, uncongenial, unconnected,
   undemonstrative, unescorted, unexpansive, unfriendly, ungenial,
   uninquiring, uninterested, uninvolved, unjoined, unmindful,
   unresponsive, unseconded, unsociable, unsocial, unsupported,
   unsympathetic, untenacious, up, upstairs, upward, upwards,
   withdrawn