We don't have synonyms for Seleucid yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are pellucid, seleucus and seleucia.
(adj) :
Relating to the Greek-Macedonian dynasty which ruled (312–63 BCE) an empire created by Seleucus out of the eastern conquests of Alexander the Great.
(adj) :
Relating to the Greek-Macedonian dynasty which ruled (312–63 BCE) an empire created by Seleucus out of the eastern conquests of Alexander the Great.