Deemster is the title of the senior judges on the Island, of which there are two.

Formerly known as North and South, they are now titled First and Second Deemster.

One family shows up in 1871:
Peel, district 2, schedule 63, 13 Patrick St
Ann Dempster, head, married, 46, wife of Alexander, Patrick
Margaret Lace, daughter, unmarried, 12, Peel
Eleanor Dempster, daughter, 5, scholar, Peel
Agnes, daughter, 2, Peel