by oneself
idiomDefinition of by oneself
1
: without any help from other people
I shoveled the driveway by myself. I want you to figure it out by yourself.
2
: with no one or nothing else : alone
The grandmother still lives in the house by herself. He went to the store by himself. They toured the city by themselves. The new law will help, but it can't solve the problem (all) by itself.