Etymology Dictionary

CAIRN,  a pile of stones.  (C.)   In Scott, Lady of the Lake, c. v. st. 14, where it rimes with 'stern.'   Particularly used of a pile of stones raised on the top of a hill, or set up as a landmark; always applied by us to a pile raised by artificial means.   Of quite modern introduction into English.  It seems to have come to us from the Gaelic in particular; and it is odd that we should have taken it in the form cairn, which is that of the genitive case, rather than from the nom. carn.   β. The form carn (a rock) is common to Gaelic, Irish, Welsh, Manx, Cornish, and Breton; the sense is, in general, 'a pile of stones,' and it was originally chiefly used of a pile of stones raised over a grave.   The Irish carn also means 'an altar.'   Cf. Gael. carn, W. carnu, to pile up, heap together.   See Chert, and Crag.