Definition of MI5 in English:

MI5

Line breaks: MI5
Pronunciation: /ɛmʌɪˈfʌɪv
 
/
(In the UK) the governmental agency responsible for dealing with internal security and counter-intelligence on British territory. Formed in 1909, the agency was officially named the Security Service in 1964, but the name MI5 remains in popular use.

Origin

from Military Intelligence section 5.

Definition of MI5 in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day glee
Pronunciation: gliː
noun
great delight, especially from one's own good fortune…