The Collaborative International Dictionary of English v.0.48:

Devout \De*vout"\, a. [OE. devot, devout, F. d['e]vot, from L.
   devotus devoted, p. p. of devovere. See Devote, v. t.]
   1. Devoted to religion or to religious feelings and duties;
      absorbed in religious exercises; given to devotion; pious;
      reverent; religious.
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            A devout man, and one that feared God. --Acts x. 2.
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            We must be constant and devout in the worship of
            God.                                  --Rogers.
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   2. Expressing devotion or piety; as, eyes devout; sighs
      devout; a devout posture. --Milton.
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   3. Warmly devoted; hearty; sincere; earnest; as, devout
      wishes for one's welfare.
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   The devout, devoutly religious persons, those who are
      sincerely pious.

   Syn: Holy; pure; religious; prayerful; pious; earnest;
        reverent; solemn; sincere.
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The Collaborative International Dictionary of English v.0.48:

Devout \De*vout"\, n.
   1. A devotee. [Obs.] --Sheldon.
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   2. A devotional composition, or part of a composition;
      devotion. [Obs.] --Milton.
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WordNet (r) 3.0 (2006):

devout
    adj 1: deeply religious; "a god-fearing and law-abiding people"
           H.L.Mencken [syn: devout, god-fearing]
    2: earnest; "one's dearest wish"; "devout wishes for their
       success"; "heartfelt condolences" [syn: dear, devout,
       earnest, heartfelt]