What name has been coined for a hill in the UK that has a drop of at least 150m on all sides?

A Marilyn is a mountain or hill in the United Kingdom, Republic of Ireland or Isle of Man with a prominence of at least 150 metres (492 ft), regardless of absolute height or other merit. The name was coined as a punning contrast to the designation Munro, used for a Scottish mountain with a height of more than 3,000 feet (914.4 m), which is homophonous with (Marilyn) Monroe.

There are 2,010 Marilyns identified: 1,218 in Scotland, 454 in Ireland (of which 65 are in Northern Ireland), 175 in England, 158 in Wales, 5 on the Isle of Man. Black Mountain, in the Black Mountains, on the border between England and Wales, was formerly counted in both countries but is now treated as being in Wales only. The list of Marilyns in Britain was compiled by Alan Dawson in his book The Relative Hills of Britain, and continues to change as newer surveys revise height measurements for hills and the cols between them. The list was extended into Ireland by Clem Clements in a booklet, The Hewitts and Marilyns of Ireland.