801 and Domesday Monachorum - a series of Domesday-related texts kept at Canterbury Cathedral - mention it as Teneham, Taenham, Tenaham and Tenham. In the Domesday Book of 1086 the name occurs as "Therham" (probably a clerical error).

The historian JK Wallenberg (in 1931) suggests an Anglo-Saxon root, tynan, to enclose, followed by the Anglo-Saxon word "Hamm", a land drained by dykes. The philologist Eilert Ekwall (in 1936)