The Collaborative International Dictionary of English v.0.48:

Earn \Earn\ ([~e]rn), v. t. [imp. & p. p. Earned ([~e]rnd); p.
   pr. & vb. n. Earning.] [AS. earnian; akin to OHG. arn[=o]n
   to reap, aran harvest, G. ernte, Goth. asans harvest, asneis
   hireling, AS. esne; cf. Icel. ["o]nn working season, work.]
   1. To merit or deserve, as by labor or service; to do that
      which entitles one to (a reward, whether the reward is
      received or not).
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            The high repute
            Which he through hazard huge must earn. --Milton.
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   2. To acquire by labor, service, or performance; to deserve
      and receive as compensation or wages; as, to earn a good
      living; to earn honors or laurels.
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            I earn that [what] I eat.             --Shak.
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            The bread I have earned by the hazard of my life or
            the sweat of my brow.                 --Burke.
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   Earned run (Baseball), a run which is made without the
      assistance of errors on the opposing side.

   Syn: See Obtain.
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WordNet (r) 3.0 (2006):

earned run
    n 1: a run that was not scored as the result of an error by the
         other team [ant: unearned run]