In French, bon means “good,”
which has lead some to believe that it is the first element of the English
all, a bonfire is a really good fire. British lexicographer Samuel Johnson also
offered up that etymology in his 1755 Dictionary of the English
Language, in which he defined bonfire as “a fire made
for some publick cause of triumph or exaltation,” and derived the word
from the French bon and the English word fire. Noah
Webster believed the same. However, the etymology was corrected in the
1890 Webster’s International Dictionary.
The word is actually derived from Middle English bonefire,
meaning literally “a fire of bones.” (Way cooler etymology, right?)
The earliest appearance of the word is glossed ignis ossium—Latin
for “fire of bones.” And a citation from the 15th century confirms
that this is not just a learned folk-etymology.
But in worshipp of seinte iohan the people woke at home
& made iij maner of fyres. On was clene bones & no wode & that is
callid a bone fyre. A nothir is clene wode & no bones & that is callid
a wode fyre fore people to sitte & to wake there by.
—John Mirk, Liber Festivalis, 1486