What it means
A turn of phrase is a neat, memorable way of wording something. It’s the little spin someone puts on a line that makes it land harder, sound sharper, or just stick in your head. It’s not really slang itself, more a handy bit of praise for someone’s wording when they’ve said it with style.
Usage examples
"Our manager called the pay freeze a team-building pause. Mate, that’s a turn of phrase worthy of a dodgy politician and a Tesco meal deal."
"She has a lovely turn of phrase, every sentence sparkles."
"That's a funny turn of phrase, I've never heard it put that way."
"He’s got a proper turn of phrase on him. Even his complaint about the bins sounded Shakespeare-adjacent."
"Calling your breakup a romantic system failure is one hell of a turn of phrase, I’ll give you that."
Where it comes from
This one’s old and straight-up literal. It comes from the idea of giving language a particular turn, meaning a twist or shaping of words into a certain form. By the 18th century, English was already using turn of phrase for someone’s distinctive way of putting things.