Quote from an article on CMC (thanks to @bitsharesgroup):

"Suez" is the Canal of the Pharaohs, also called the Ancient Suez Canal or Necho's Canal, is the forerunner of the Suez Canal, constructed in ancient times and kept in use, with intermissions, it followed a different course from its modern counterpart, by linking the Nile to the Red Sea via the Wadi Tumilat. Work began under the pharaohs. According to Darius the Great's Suez Inscriptions and Herodotus, the first opening of the canal was under Persian king Darius the Great.
BitShares Blockchain community is an international community carrying an open source work together in an agile style; the release was called "Suez" in order to represent the diversified community behind BitShares Blockchain and to connect with worldwide users as the rivers connecting world societies together.