Hearing 'butcher' in everyday English usually makes me think of something horribly mishandled rather than the person who sells meat. In casual speech people say someone 'butchered' a task, a song, a pronunciation — it simply means they totally messed it up. I hear it at karaoke nights all the time: ‘‘You butchered that chorus,’’ which is blunt but playful among friends. It can be used lightly — like joking about a clumsy attempt at a recipe — or sharply, when someone really wrecks a delicate thing, like an elegant translation.
There’s also a darker, more literal slang edge: calling someone a butcher can imply cruelty or violence. If someone says ‘‘he’s a butcher’’ about a fighter or a historical figure, they mean he’s brutal. That’s a stronger, more insulting usage and not something to toss around casually. For a regional twist, British folks sometimes say ‘‘have a butcher’s’’ — short for the Cockney rhyming slang 'butcher's hook' meaning 'look' — so you'd be invited to ‘‘have a butcher’s at this,’’ i.e., take a look.
So context is everything: playful critique, harsh insult, or old-school slang for 'look.' I tend to watch tone and who’s around before I use it, since it can land as funny or cutting depending on the moment — a small word with surprisingly big variety, and I still enjoy dropping the Cockney bit for laughs sometimes.