noun

• (Ireland) Woven wool or flannel; especially undyed, unbleached wool.
  "Granna's rag rug still lay on the floor near the hearth, but it was more rag than rug now, and terribly dirty beside. The bawneen curtains were gone from the window, having been used to make bedding for wee Thomsy's cradle; [...]"
• (Ireland) A traditional Irish "Aran" sweater.
  "I noticed she was looking closely at my jumper. [...] I remembered a bit of folklore I'd once heard that Island women used to weave secret patterns into their husbands' fishing bawneens to warn other women they were spoken for."
• (Ireland) A waistcoat with sleeves, typically worn by labourers and fishermen.
  "Out of the flannel the women made what were called bawneens for the men. A bawneen was a kind of sleeved waistcoat, buttoning up the front. Often trousers were made of this flannel, too."