Obs. Also bonilass. Now written as two words: Bonny lass.

1

1546.  Bale, Eng. Votaries, I. (R.). And so become byshoppes bonilasses.

2

1579.  Spenser, Sheph. Cal., Aug. (L.). As the bonnilasse passed by. Ibid., Aug., 78. Hey ho bonilasse.

3