We don't have synonyms for smyth yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are myth, smith and scyth.
(n) :
Obsolete spelling of smith. [A craftsperson who works metal into desired forms using a hammer and other tools, sometimes heating the metal to make it more workable, especially a blacksmith.]
(n) :
Obsolete spelling of smith. [A craftsperson who works metal into desired forms using a hammer and other tools, sometimes heating the metal to make it more workable, especially a blacksmith.]