Deem
Most likely from an old word for a judge or law-speaker, with roots in the idea of “to judge” or “to deem.”
The #9,917 most common surname in the United States (2010 Census) — about 1 in every 94,765 Americans shares it.
Etymology
This surname is usually explained as coming from an occupational or official term meaning “judge” or “one who gives a legal decision.” The underlying word is the same one behind modern English "deem," which once meant "judge" or "pronounce." Some antiquarian writers connect it with the northern and Manx legal title "deemster," a law officer in the Isle of Man.
History
The historical excerpts point especially to the Manx and northern British legal title "deemster," which was the name of a judge or law-speaker. As a surname, Deem would fit the common medieval pattern of surnames taken from offices or roles. In English records it is uncommon, and modern bearers in the United States are relatively few.
Origin
Regions
Variant spellings
Fun fact
The old verb "to deem" once meant not just “think,” but specifically “judge” or “give a ruling.”
From the historical record
“deemer,' a judge, one who pro- nounced the verdict or doom ; v. Dempster. When we say, 'I deem so.'wemean 'Ijudgeso.' 'Denur (ordomesman,P,),/ii^cafar(/KA:i^ P.)': Prompt. Pan-, p. iiB. Sbnon le Demer : Calendarlun Inqalii- iOBBm Foal Msnem (t. iadea).”
— A Dictionary of English and Welsh Surnames, with special American instances