We don't have synonyms for arguendo yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are arundo, argued and argento.
(adv) :
(law) for the sake of argument; assuming without deciding; identifying the premises of a hypothetical argument while making it clear that no finding is being made on whether the premises are true.
(adv) :
(law) Used to set off the facts presented in an argument on a point of law from facts in dispute in the case.
(adv) :
(law) for the sake of argument; assuming without deciding; identifying the premises of a hypothetical argument while making it clear that no finding is being made on whether the premises are true.
(adv) :
(law) Used to set off the facts presented in an argument on a point of law from facts in dispute in the case.