a county in southern England
"The rolling hills and historic towns of Hertfordshire make it a popular destination for day trips from London."
An inland county of south-east England bordered by Cambridgeshire, Essex, Greater London, Buckinghamshire and Bedfordshire.
"Hertfordshire is an inland county of south-east England bordered by Cambridgeshire, Essex, Greater London, Buckinghamshire, and Bedfordshire."
The name comes from combining the town of Hertford with the suffix "-shire," which was used in Middle English to denote a county or shire district. This formation directly created the modern administrative region known as Hertfordshire.