The Collaborative International Dictionary of English v.0.48:

Exert \Ex*ert"\, v. t. [imp. & p. p. Exerted; p. pr. & vb. n.
   Exerting.] [L. exertus, exsertus, p. p. of exerere,
   exserere, to thrust out; ex out + serere to join or bind
   together. See Series, and cf. Exsert.]
   1. To thrust forth; to emit; to push out. [Obs.]
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            So from the seas exerts his radiant head
            The star by whom the lights of heaven are led.
                                                  --Dryden.
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   2. To put force, ability, or anything of the nature of an
      active faculty; to put in vigorous action; to bring into
      active operation; as, to exert the strength of the body,
      limbs, faculties, or imagination; to exert the mind or the
      voice.
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   3. To put forth, as the result or exercise of effort; to
      bring to bear; to do or perform.
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            When we will has exerted an act of command on any
            faculty of the soul or member of the body. --South.
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   To exert one's self, to use efforts or endeavors; to
      strive; to make an attempt.
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