rotten borough

rotten borough (plural rotten boroughs)

1. (historical) A borough that was represented in Parliament although it had very few voters.
   • 1848, William Makepeace Thackeray, Vanity Fair, Chapter 7:

     Queen's Crawley was no longer so populous a place as it had been in Queen Bess's time—nay, was come down to that condition of borough which used to be denominated rotten–yet, as Sir Pitt Crawley would say with perfect justice in his elegant way, "Rotten! be hanged—it produces me a good fifteen hundred a year."

• This term refers to Great Britain before 1832.

• pocket borough
• safe seat