The Collaborative International Dictionary of English v.0.48:

Inundation \In`un*da"tion\, n. [L. inundatio: cf. F.
   inondation.]
   [1913 Webster]
   1. The act of inundating, or the state of being inundated; an
      overflow; a flood; a rising and spreading of water over
      grounds.
      [1913 Webster]

            With inundation wide the deluge reigns,
            Drowns the deep valleys, and o'erspreads the plains.
                                                  --Wilkie.
      [1913 Webster]

   2. An overspreading of any kind; overflowing or superfluous
      abundance; a flood; a great influx; as, an inundation of
      tourists.
      [1913 Webster]

            To stop the inundation of her tears.  --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

inundation
    n 1: the rising of a body of water and its overflowing onto
         normally dry land; "plains fertilized by annual
         inundations" [syn: flood, inundation, deluge,
         alluvion]
    2: an overwhelming number or amount; "a flood of requests"; "a
       torrent of abuse" [syn: flood, inundation, deluge,
       torrent]