by chance

Poor cottagers living beside a highroad don't open too easily at this hour to a couple of come-by-chance wayfarers.

By nature, I mean simply the present state of things, whether designed by an intelligent mind, or a mere come-by-chance.

It was whispered about that you were a come-by-chance child, and your mother was a bad woman.

So you see, I am a come by-chance, and I have been going by chance all of my life.

In the excitement of carpentering incidental to the cloudburst, the crew of the train omitted to drop it off at Come-by-Chance.