[1] : The Collaborative International Dictionary of English v.0.48

camber \cam"ber\, n. of. cambre bent, curved; akin to f.
   cambrer to vault, to bend, fr. l. camerare to arch over, fr.
   camera vault, arch. see chamber, and cf. camerate.
   1. shipbuilding an upward convexity of a deck or other
      surface; as, she has a high camber said of a vessel
      having an unusual convexity of deck.
      1913 webster

   2. arch. an upward concavity in the under side of a beam,
      girder, or lintel; also, a slight upward concavity in a
      straight arch. see hogback.
      1913 webster

   camber arch arch., an arch whose intrados, though
      apparently straight, has a slightly concave curve upward.
      

   camber beam arch., a beam whose under side has a concave
      curve upward.
      1913 webster
see also:
chamber camerate hogback camber arch camber beam 

[2] : WordNet (r) 2.0

camber arch
     n : an arch with a straight horizontal extrados and a slightly
         arched intrados

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Aortic Arch, definition of term: Aortic Arch
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