go off the rails
phrase
informal
: to lose control and start to behave in a way that is not normal or acceptable
He was a promising student but he went off the rails after he started taking drugs.
Cite this Entry
“Go off the rails.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/go%20off%20the%20rails. Accessed 10 Mar. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
