Definition of "whin"

By this time he was cross the ford, / Whare in the snaw the chapman smoor'd; / And past the birks and meikle stane, / Whare drunken Charlie brak's neck-bane; / And through the whins, and by the cairn, / Whare hunters fand the murder'd bairn; / And near the thorn, aboon the well, / Whare Mungo's mither hang'd hersel.

1790, Robert Burns, Tam o' Shanter, 1828, Thomas Park (editor), Works of the British Poets, Volume XX: The Poems of Robert Burns, page 65

And sometimes they clambered down […] and saw the whin bushes climb black the white hills beside them and far and away the blink of lights across the moors where folk lay happed and warm.

1932, Lewis Grassic Gibbon, “Sunset Song”, in A Scots Quair, Canongate Books, published 1995, page 38