butty
noun
1
a sandwich. Also spelt 'buttie'. Originally used in northern England, especially Liverpool, as a dialect elision of 'buttery'; now widespread, especially as 'jam butty', 'chip butty', etc UK, 1855.
2
a non-powered, towed canal boat that is part of a working pair. Also known as a 'butty boat' UK, 1944.
3
a friend, a workmate; also used as a form of address. Variants are 'butt' and 'buttie'. Either from mining where 'butty' was 'a middleman', or from Romany booty-pal (a fellow workman) or, most probably, Warwickshire dialect butty (a fellow servant or labourer). Modern use may be influenced by BUDDY UK, 1859