The phrase "by mistake" means unintentionally or accidentally. It is used to describe an action that was done incorrectly, inadvertently or wrongly due to a misunderstanding or error.
Sentences with «by mistake»
Don't be undermined by mistakes in your writing, or if writing just isn't your strong point — we can help! (editingboston.com)
Would anyone really say that those killed by computer - driven cars have been harmed more than those killed by the mistakes of human drivers? (firstthings.com)
These important fossils, like so many others, were essentially found by mistake. (scientificamerican.com)