(in Britain) short for Stewardship of the Chiltern Hundreds; a nominal office that an MP applies for in order to resign his or her seat
Chiltern hundreds in American English
(ˈtʃɪltərn)
British
a purely nominal office held from the crown: appointment to it avoids application of the rule that members of Parliament wishing to vacate their seats may not resign
Word origin
from the tract of crown lands in SC England, containing the Chiltern Hills