derail

1 ENTRIES FOUND:
derail /dɪˈreɪl/ verb
derails; derailed; derailing
derail
/dɪˈreɪl/
verb
derails; derailed; derailing
Britannica Dictionary definition of DERAIL
1 
[no object] of a train : to leave its tracks
2 
[+ object] : to cause (a train) to leave its tracks — often used figuratively

— derailment

/dɪˈreɪlmənt/ noun, plural derailments