Definition of "bonnie"

bonnie¹

adjective
comparative bonnier or more bonnie, superlative bonniest or most bonnie
1. Merry; happy.
  Quotations
  Be you blithe and bonnyConverting all your sounds of woeInto Hey nonny, nonny.
  1598–1599 (first performance), William Shakespeare, “Much Adoe about Nothing”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, (please specify the act number in uppercase Roman numerals, and the scene number in lowercase Roman numerals)
2. (Scotland, Geordie) Beautiful; pretty; attractive; handsome.
  Quotations
  O once I lov'd a bonnie lass, / Aye, and I love her still
  1774, “Handsome Nell”, Robert Burns (lyrics), published 1803
3. (Scotland, Geordie) Fine, good (often used ironically).

bonnie²

noun
plural bonnies
1. (Northern Ireland, colloquial) Bonfire; chiefly one several storeys tall burnt to celebrate Eleventh Night.