We don't have synonyms for margiana yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are marina, margin and mariana.
(N) :
(Margianḗ, Old Persian: Marguš, Middle Persian: Marv) a historical region centred on the oasis of Merv and was a minor satrapy within the Achaemenid satrapy of Bactria, and a province within its successors, the Seleucid, Parthian and Sasanian empires.
(N) :
(Margianḗ, Old Persian: Marguš, Middle Persian: Marv) a historical region centred on the oasis of Merv and was a minor satrapy within the Achaemenid satrapy of Bactria, and a province within its successors, the Seleucid, Parthian and Sasanian empires.