The Collaborative International Dictionary of English v.0.48:

Lower \Low"er\, v. i. [imp. & p. p. Lowered; p. pr. & vb. n.
   Lowering.] [OE. lowren, luren; cf. D. loeren, LG. luren. G.
   lauern to lurk, to be on the watch, and E. leer, lurk.]
   1. To be dark, gloomy, and threatening, as clouds; to be
      covered with dark and threatening clouds, as the sky; to
      show threatening signs of approach, as a tempest.
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            All the clouds that lowered upon our house. --Shak.
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   2. To frown; to look sullen.
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            But sullen discontent sat lowering on her face.
                                                  --Dryden.
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The Collaborative International Dictionary of English v.0.48:

Lower \Low"er\, v. t. [imp. & p. p. Lowered; p. pr. & vb. n.
   Lowering.] [From Low, a.]
   1. To let descend by its own weight, as something suspended;
      to let down; as, to lower a bucket into a well; to lower a
      sail or a boat; sometimes, to pull down; as, to lower a
      flag.
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            Lowered softly with a threefold cord of love
            Down to a silent grave.               --Tennyson.
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   2. To reduce the height of; as, to lower a fence or wall; to
      lower a chimney or turret.
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   3. To depress as to direction; as, to lower the aim of a gun;
      to make less elevated as to object; as, to lower one's
      ambition, aspirations, or hopes.
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   4. To reduce the degree, intensity, strength, etc., of; as,
      to lower the temperature of anything; to lower one's
      vitality; to lower distilled liquors.
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   5. To bring down; to humble; as, to lower one's pride.
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   6. To reduce in value, amount, etc.; as, to lower the price
      of goods, the rate of interest, etc.
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The Collaborative International Dictionary of English v.0.48:

lowered \lowered\ adj.
   pointed downward; as, with lowered eyes. Opposite of
   raised.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

lowered
    adj 1: below the surround or below the normal position; "with
           lowered eyes" [ant: raised]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "lowered":
   abated, ablated, attenuated, bated, belittled, bowed down,
   brought down, brought low, consumed, contracted, curtailed,
   debased, decreased, deflated, depressed, diminished, dissipated,
   downcast, downthrown, dropped, eroded, fallen, humbled,
   in the dust, less, lesser, low, lower, miniaturized, prostrate,
   reduced, retrenched, scaled-down, set down, shorn, shorter, shrunk,
   shrunken, smaller, submerged, sunk, sunken, watered-down, weakened,
   worn