Source : Webster's Revised Unabridged Dictionary (1913)

Imagine \Im*ag"ine\, v. i.
   1. To form images or conceptions; to conceive; to devise.

   2. To think; to suppose.

            My sister is not so defenseless left As you imagine.
                                                  --Milton.

Imagine \Im*ag"ine\, v. t. [imp. & p. p. {Imagined}; p. pr. &
   vb. n. {Imagining}.] [F. imaginer, L. imaginari, p. p.
   imaginatus, fr. imago image. See {Image}.]
   1. To form in the mind a notion or idea of; to form a mental
      image of; to conceive; to produce by the imagination.

            In the night, imagining some fear, How easy is a
            bush supposed a bear!                 --Shak.

   2. To contrive in purpose; to scheme; to devise; to compass;
      to purpose. See {Compass}, v. t., 5.

            How long will ye imagine mischief against a man?
                                                  --Ps. lxii. 3.

   3. To represent to one's self; to think; to believe. --Shak.

   Syn: To fancy; conceive; apprehend; think; believe; suppose;
        opine; deem; plan; scheme; devise.

Source : WordNet®

imagine
     v 1: form a mental image of something that is not present or that
          is not the case; "Can you conceive of him as the
          president?" [syn: {conceive of}, {ideate}, {envisage}]
     2: expect, believe, or suppose; "I imagine she earned a lot of
        money with her new novel"; "I thought to find her in a bad
        state"; "he didn't think to find her in the kitchen"; "I
        guess she is angry at me for standing her up" [syn: {think},
         {opine}, {suppose}, {reckon}, {guess}]