From The Collaborative International Dictionary of English v.0.48 :
Bonfire \Bon"fire`\, n. [OE. bonefire, banefire, orig. a fire of
bones; bone + fire; but cf. also Prov. E. bun a dry stalk.]
A large fire built in the open air, as an expression of
public joy and exultation, or for amusement.
[1913 Webster]
Full soon by bonfire and by bell,
We learnt our liege was passing well. --Gay.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
bonfire
n 1: a large outdoor fire that is lighted as a signal or in
celebration [syn: bonfire, balefire]