Interested in Language
"Is there an English idiom that has the same/similar meaning?"
Is it correct or not?
Although "the same meaning" works, "the similar meaning" doesn't so you can't use the definite article and try to attach it to both adjectives.
Is there an English idiom that has the same, or a similar, meaning?
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.