The Collaborative International Dictionary of English v.0.48:

Whelm \Whelm\, v. t. [imp. & p. p. Whelmed; p. pr. & vb. n.
   Whelming.] [OE. whelmen to turn over, akin to OE. whelven,
   AS. whelfan, hwylfan, in ?whylfan, ?whelfan, to overwhelm,
   cover over; akin to OS. bihwelbian, D. welven to arch, G.
   w["o]lben, OHG. welben, Icel. hvelfa to overturn; cf. Gr. ?
   bosom, a hollow, a gulf.]
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   1. To cover with water or other fluid; to cover by immersion
      in something that envelops on all sides; to overwhelm; to
      ingulf.
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            She is my prize, or ocean whelm them all! --Shak.
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            The whelming billow and the faithless oar. --Gay.
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   2. Fig.: To cover completely, as if with water; to immerse;
      to overcome; as, to whelm one in sorrows. "The whelming
      weight of crime." --J. H. Newman.
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   3. To throw (something) over a thing so as to cover it.
      [Obs.] --Mortimer.
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