On Stumbling Block Meaning?

1 : an obstacle to progress. 2 : an impediment to belief or understanding : perplexity.

Is a stumbling block an idiom?

A challenge or hindrance that prevents something from being accomplished. Stay away from your old friends—their drug use will be a stumbling block in your recovery from alcoholism.

What does stumble on mean?

Definition of stumble across/on/onto/upon

: to find or learn about (something) unexpectedly I stumbled across/on/upon this book by chance. We stumbled onto/across the ruins of an old fort. They stumbled on/upon a bizarre plot. He stumbled onto the truth.