Definition from Wiktionary, the free dictionary
constituency (plural constituencies)
- A district represented by one or more elected officials.
- John was elected to parliament from the Bedford constituency.
- 2011 December 14, Angelique Chrisafis, “Rachida Dati accuses French PM of sexism and elitism”, Guardian:
- The row started over who will run for parliament in a wealthy rightwing constituency on the left bank in Paris, a safe seat for Sarkozy's ruling UMP. Dati is already a local mayor in the neighbourhood, a job felt to have been handed to her on a plate when she was a Sarkozy favourite. She has since fallen from grace, and when she left government she took a European parliament seat, considered a consolation prize.
- The voters within such a district.
- An interest group or fan base.
Related terms 
district represented by one or more elected officials
voters within such a district — see electorate