Definition
To override is to overrule — to set aside an existing rule, decision, or automatic process by force of higher authority. A manual switch overrides the autopilot; a court overrides a lower ruling; a strong instinct can override reason. From 'ride over', it carries the sense of one force riding straight over another and taking control. What is overridden is not destroyed but suspended: it would still run the moment the stronger signal stepped away, which is exactly why an override has to be held in place.
Examples
Collocations
override the decision·a manual override·override the system·override an objection
Synonyms
overrule·supersede·countermand·veto·nullify
Antonyms
uphold·defer to·comply with
Word family
override (noun)·overriding (adjective)
In TOEFL & IELTS
Common in TOEFL passages on technology and governance and useful in IELTS as a strong verb for authority ('the minister can override local councils'). It works as a noun too ('a manual override'). Keep the stress on the last syllable for the verb, and pair it with 'decision', 'system' and 'objection'.