Tumps are hills, of any height, with a drop of 30 metres or more on all sides  The name Tump stands for Thirty and Upward Metre Prominence. By definition, all Marilyns, sub-Marilyns, HuMPs, and sub-HuMPs qualify as Tumps.

They should not be confused with the English word tump, derived from the Welch word twmp, which means hillock or mound. There are a number of small hills with Tump in their name around Gloucestershire and the Welsh borders, such as Hetty Pegler’s Tump and Wormelow Tump.

There are 5973 Tumps in England and Wales, 3637 in England and 2336 in Wales. Discluding those hills which are classified as Marilyns, sub-Marilyns, HuMPs, or sub-HuMPs, we are left with 4990 Tumps in England and Wales, 3097 in England and 1893 in Wales.