Derail

Part of speech: verb

Pronunciation: /ˌdəˈɹeɪ.əl/

Definitions

1. To cause a train to go off track or to obstruct the progress of any plan or event, thereby leading to an undesired outcome of actions or intentions
2. To force a train to leave the rails unexpectedly ; to hinder or stop the successful continuation of a plan or effort
3. To make railway vehicles come off their tracks deliberately or accidentally ; to obstruct or interrupt the normal progress of an activity or scheme

Etymology: The verb "derail" arrived in English from French "dérailler", meaning "to go off the rails," and the French verb is itself built from "dé-", a prefix meaning "away" or "off," and "rail," the familiar word for a track. The picture is literal: a wheel that leaves its rail has left the path that was supposed to carry it. That is why the sense of a train leaving its track came first, and the broader sense of any plan or event knocked off its intended course grew out of it. The English word is easy to analyze because both of its parts are still visible. "De-" is the same prefix found in words like "deform" and "decamp," where it signals removal, reversal or departure, and "rail" comes from Old French "reille" and Latin "regula," a rule or bar. So a derailed plan is one that has been pushed off the bar that was keeping it in line.

Synonyms: disrupt, prevent

Antonyms: facilitate, enable