The Collaborative International Dictionary of English v.0.48:

Summit \Sum"mit\, n. [F. sommet, dim. of OF. som, sum, top, from
   L. summum, from summus highest. See Sum, n.]
   1. The top; the highest point.
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            Fixed on the summit of the highest mount. --Shak.
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   2. The highest degree; the utmost elevation; the acme; as,
      the summit of human fame.
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   3. (Zool.) The most elevated part of a bivalve shell, or the
      part in which the hinge is situated.
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   Summit level, the highest level of a canal, a railroad, or
      the like, in surmounting an ascent.
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