Source : Webster's Revised Unabridged Dictionary (1913)

Iambic \I*am"bic\, a. [L. iambicus, Gr. ?: cf. F. iambique.]
   1. (Pros.) Consisting of a short syllable followed by a long
      one, or of an unaccented syllable followed by an accented;
      as, an iambic foot.

   2. Pertaining to, or composed of, iambics; as, an iambic
      verse; iambic meter. See {Lambus}.

Iambic \I*am"bic\, n.
   1. (Pros.)
      (a) An iambic foot; an iambus.
      (b) A verse composed of iambic feet.

   Note: The following couplet consists of iambic verses.

               Thy gen- | ius calls | thee not | to pur- | chase
               fame In keen | iam- | bics, but | mild an- |
               agram.                             --Dryden.

   2. A satirical poem (such poems having been anciently written
      in iambic verse); a satire; a lampoon.

Source : WordNet®

iambic
     adj : of or consisting of iambs; "iambic pentameter"
     n : a verse line consisting of iambs