The Collaborative International Dictionary of English v.0.48:

Dilation \Di*la"tion\, n. [L. dilatio. See Dilatory.]
   Delay. [Obs.] --Bp. Hall.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dilation \Di*la"tion\, n. [From dilate, v., cf. Dilatation,
   Dilator.]
   The act of dilating, or the state of being dilated;
   expansion; dilatation. --Mrs. Browning.
   [1913 Webster]

         At first her eye with slow dilation rolled. --Tennyson.
   [1913 Webster]

         A gigantic dilation of the hateful figure. --Dickens.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dilation
    n 1: a lengthy discussion (spoken or written) on a particular
         topic
    2: the act of expanding an aperture; "the dilation of the pupil
       of the eye" [syn: dilation, dilatation]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "dilation":
   aggrandizement, amplification, ballyhoo, big talk, bloat,
   bloatedness, bloating, blowing up, boil, bump, bunion, burlesque,
   carbuncle, caricature, corn, cyst, development, diastole,
   dilatation, distension, dropsy, edema, elaboration, enhancement,
   enlargement, exaggerating, exaggeration, excess, exorbitance,
   expansion, expatiation, explication, extravagance, extreme,
   flatulence, flatulency, flatus, furuncle, gassiness,
   grandiloquence, heightening, huckstering, hyperbole, hyperbolism,
   inflation, inordinacy, intumescence, lump, magnification,
   meteorism, overemphasis, overestimation, overkill, overstatement,
   pimple, pock, prodigality, profuseness, puff, puffery, puffiness,
   puffing, puffing up, pustule, rising, sebaceous cyst,
   sensationalism, stretching, superlative, swell, swellage, swelling,
   swollenness, tall talk, touting, travesty, tumefaction, tumescence,
   tumidity, tumidness, tumor, turgescence, turgescency, turgidity,
   turgidness, tympanism, tympany, unfolding, wen, windiness,
   working-out