The Collaborative International Dictionary of English v.0.48:

Breath \Breath\ (br[e^]th), n. [OE. breth, breeth, AS.
   br[=ae][eth] odor, scent, breath; cf. OHG. br[=a]dam steam,
   vapor, breath, G. brodem, and possibly E. Brawn, and
   Breed.]
   1. The air inhaled and exhaled in respiration; air which, in
      the process of respiration, has parted with oxygen and has
      received carbonic acid, aqueous vapor, warmth, etc.
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            Melted as breath into the wind.       --Shak.
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   2. The act of breathing naturally or freely; the power or
      capacity to breathe freely; as, I am out of breath.
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   3. The power of respiration, and hence, life. --Hood.
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            Thou takest away their breath, they die. --Ps. civ.
                                                  29.
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   4. Time to breathe; respite; pause.
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            Give me some breath, some little pause. --Shak.
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   5. A single respiration, or the time of making it; a single
      act; an instant.
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            He smiles and he frowns in a breath.  --Dryden.
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   6. Fig.: That which gives or strengthens life.
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            The earthquake voice of victory,
            To thee the breath of life.           --Byron.
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   7. A single word; the slightest effort; a trifle.
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            A breath can make them, as a breath has made.
                                                  --Goldsmith.
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   8. A very slight breeze; air in gentle motion.
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            Calm and unruffled as a summer's sea,
            when not a breath of wind flies o'er its surface.
                                                  --Addison.
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   9. Fragrance; exhalation; odor; perfume. --Tennison.
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            The breath of flowers.                --Bacon.
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   10. Gentle exercise, causing a quicker respiration.
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             An after dinner's breath.            --Shak.
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   Out of breath, breathless, exhausted; breathing with
      difficulty.

   Under one's breath, in low tones.
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WordNet (r) 3.0 (2006):

breath
    n 1: the process of taking in and expelling air during
         breathing; "he took a deep breath and dived into the pool";
         "he was fighting to his last breath"
    2: the air that is inhaled and exhaled in respiration; "his sour
       breath offended her"
    3: a short respite [syn: breath, breather, breathing
       place, breathing space, breathing spell, breathing
       time]
    4: an indirect suggestion; "not a breath of scandal ever touched
       her" [syn: hint, intimation, breath]
    5: a slight movement of the air; "there wasn't a breath of air
       in the room"