by mistake
Accidentally; unintentionally. I am so sorry, sir—I gave you the wrong dish by mistake. Oh, they hung up—they called the wrong number by mistake.
by mistake
in error; accidentally. I'm sorry. I came into the wrong room by mistake. I chose the wrong road by mistake. Now we are lost.
by mistake
Erroneously, as in He took my coat by mistake. [c. 1700]
by miˈstake
accidentally; without intending to: I took your bag instead of mine by mistake.