Definition of "bast"

[T]here would be seen his face, or that of his elder brother, peering down. A guttural sound, and the tip-tap of bast slippers beating the narrow wooden stairs, and he would stand before one without coat, a little bent, in leather apron, with sleeves turned back, blinking […]

1912, John Galsworthy, Quality

At the far end of the houses the head gardener stood waiting for his mistress, and he gave her strips of bass to tie up her nosegay. This she did slowly and laboriously, with knuckly old fingers that shook.

1918, W[illiam] B[abington] Maxwell, chapter XIX, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company

I thought I saw Him in the Long Walk there, by the bed of Nelly Roche, tending a fallen flower with a wisp of bast.

1919, Ronald Firbank, Valmouth, Duckworth, hardback edition, page 87

He had taken along a long bast rope in his sleigh, since it was the custom on longer journeys to have a spare rope in case the reins needed mending.

1997, ‘Egil's Saga’, translated by Bernard Scudder, The Sagas of Icelanders, Penguin, published 2001, page 145