Meaning of the word "county borough" in English

What does "county borough" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

county borough

US /ˈkaʊnti ˈbɜːroʊ/
UK /ˈkaʊnti ˈbʌrə/

Noun

a borough that is administratively independent of the county in which it is geographically located

Example:
The city was designated a county borough in 1889, giving it greater autonomy.
Many county boroughs were abolished or reorganized in the 1970s.