We don't have synonyms for hand-waving yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hand waving, handwaving and hand-washing.
(n) :
Alternative spelling of hand waving. [(idiomatic) Discussion or argumentation involving approximation, vagueness, educated guessing, or the attempt to explain or excuse vagaries.]
(adj) :
Alternative spelling of handwaving. [(not comparable) Waving the hands.]
(n) :
Alternative spelling of hand waving. [(idiomatic) Discussion or argumentation involving approximation, vagueness, educated guessing, or the attempt to explain or excuse vagaries.]
(adj) :
Alternative spelling of handwaving. [(not comparable) Waving the hands.]