dolmen: [19] English acquired the word dolmen for a ‘prehistoric structure of two upright stones surmounted by a horizontal one’ from French, but its ultimate source is Celtic. The element men means ‘stone’ (it occurs also in menhir [19], literally ‘long stone’) but there is disagreement about the first syllable. It is usually said to represent tōl ‘table’, a Breton borrowing from Latin tabula ‘board, plank’, but another view is that it is Cornish tol ‘hole’, and that the compound as a whole means literally ‘stone hole’, a reference to the aperture formed by the top stone lying on the two side stones. => menhir[dolmen etymology, dolmen origin, 英语词源]