We don't have synonyms for butteris yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are butter, buttery and butters.
(n) :
(historical, farriery) A cutting instrument, with a long bent shank set in a handle which rests against the farrier's shoulder, used in paring the hoofs of horses.
(n) :
(historical, farriery) A cutting instrument, with a long bent shank set in a handle which rests against the farrier's shoulder, used in paring the hoofs of horses.