Chiltern Hills

[chil-tern]
noun (used with a plural verb)
  1. a range of chalk hills in Oxford and Buckinghamshire, S England. Highest peak, Coombe Hill, 852 feet (260 meters).
Also called Chil·terns.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for chiltern hills

Chiltern Hills

pl n
  1. a range of low chalk hills in SE England extending northwards from the Thames valley. Highest point: 260 m (852 ft)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012