MI5

[em-ahy-fahyv]

noun

1. the government's security and counterespionage service that works in liaison with Scotland Yard's Special Branch.

MI5

abbreviation

1. Military Intelligence, section five; a former official and present-day popular name for the counterintelligence agency of the British Government

Word History and Origins

Origin of MI5¹

M(ilitary) I(ntelligence, Section) 5

Example Sentences

Recently, MI5 admitted it had illegally obtained communications data from the mobile phone of journalist Vincent Kearney while he worked at the BBC.

From BBC

But different agencies - including Prevent, MI5 and social services - appeared to pass his case between them, the inquiry heard.

From BBC

But on each occasion, including after a multi-agency meeting with MI5, the referrals were closed by counter terrorism officers because no "terrorist or domestic extremist ideology" was identified.

From BBC

Sir Keir Starmer's direction follows requests from the High Court and Investigatory Powers Tribunal, which both rejected MI5's explanations about what happened.

From BBC

The case centres on a neo-Nazi state informant known as Agent X who used his MI5 role to coerce his girlfriend, whom he attacked with a machete.

From BBC