Douglas Harper's Etymology Dictionary
1803, in reference to dynasty founded in Syria 312 B.C.E. by Seleucus Nicator, general of Alexander. It lasted until the Roman conquest 65 B.C.E. The Seleucidan Era, a local reckoning in the East (maintained by Syrian Christians) usually is dated to Sept. 1, 312 B.C.E.
Wiktionary
n. (context zoology English) Any member of the Seleucidae.
Usage examples of "seleucid".
Palace : Palace of the Hasmonaean or Maccabean dynasty, rulers of Judea in the second century BC, who resisted the Seleucid kings Antiochus IV and Demetrius Soter.
In terraces up the slopes of Mount Cynthus were the precincts and temples of those gods imported to Delos during the years when it had lain under the patronage of the Ptolemies of Egypt and the Seleucids of Syria.
Pompey then made Syria a Roman province, which left the last of the Seleucids to occupy the throne of Commagene.
My workmen took up the task and Athens again felt the joy of activity such as she had not known since the days of Pericles: I was completing what one of the Seleucids had aspired in vain to finish, and was making amends in kind for the depredations of our Sulla.
Thus, in the last period of cuneiform writing, in colophons written at Uruk (in present-day Iraq) under the Seleucid kings in the last few score years before the Christian era, occasional scribes converted their names into numbers.