Source : Webster's Revised Unabridged Dictionary (1913)

Irradiate \Ir*ra"di*ate\, v. t. [imp. & p. p. {Irradiated}; p.
   pr. & vb. n. {Irradiating}.] [L. irradiatus, p. p. of
   irradiate. See {In-} in, and {Radiate}.]
   1. To throw rays of light upon; to illuminate; to brighten;
      to adorn with luster.

            Thy smile irradiates yon blue fields. --Sir W.
                                                  Jones.

   2. To enlighten intellectually; to illuminate; as, to
      irradiate the mind. --Bp. Bull.

   3. To animate by heat or light. --Sir M. Hale.

   4. To radiate, shed, or diffuse.

            A splendid fa?ade, . . . irradiating hospitality.
                                                  --H. James.

Irradiate \Ir*ra"di*ate\, v. i.
   To emit rays; to shine.

Irradiate \Ir*ra"di*ate\, a. [L. irradiatus, p. p.]
   Illuminated; irradiated. --Mason.

Source : WordNet®

irradiate
     v 1: give spiritual insight to; in religion [syn: {enlighten}]
     2: cast rays of light upon
     3: expose to radiation; "irradiate food" [syn: {ray}]