We don't have synonyms for buttie yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are butte, bittie and cuttie.
(n) :
Alternative spelling of butty. [(UK, chiefly Northern England, New Zealand, Ireland) A sandwich, usually with a hot or cold savoury filling buttered in a barmcake. The most common are chips, bacon, sausage and egg.]
(n) :
Alternative spelling of butty. [(UK, chiefly Northern England, New Zealand, Ireland) A sandwich, usually with a hot or cold savoury filling buttered in a barmcake. The most common are chips, bacon, sausage and egg.]