Bonfire
late Middle English: from bone + fire. The term originally denoted a large open-air fire on which bones were burnt (sometimes as part of a celebration), also one for burning heretics or proscribed literature. Dr Johnson accepted the mistaken idea that the word came from French bon ‘good’.
wiktionary
From Middle English bonnefyre, banefyre(“a fire in which bones are burnt”); equivalent to bone + fire, [1] with the first element perhaps later assimilating to French bon. [2] Cognate with Scots banefire(“bonfire”).
etymonline
bonfire (n.)
1550s, from Middle English banefire (late 15c.), "a fire in which bones are burned." See bone (n.) + fire (n.). Original sense obsolete and forgotten by 18c.; as "large open-air fire for public amusement or celebration," from late 15c. From 17c. as "large fire from any material,"
