Is there a heavy usage of the word "bonfire" in English?

Solution 1:

Bonfire is in common usage in the UK today, where it means any outdoor fire, normally built from wood or rubbish. As commenters have noted, in American and Canadian usage, a bonfire is specifically a large outdoor fire, but it's still a perfectly common word.

Some think that ‘bonfire’ is a mix of the French "bon" meaning "good" and the English Anglo-Saxon “fire”. Early believers included the British lexicographer Samuel Johnson, who offered up that etymology in his 1755 Dictionary of the English Language.

Johnson defined bonfire as:

"a fire made for some publick cause of triumph or exaltation,"

He derived the word from the French bon and the English word fire - the phenomenon of combustion manifested in light, flame, and heat.

However, the etymology was changed in the 1890 Webster's International Dictionary, where it is shown as derived from Middle English bonefire, meaning literally "a fire of bones."

The earliest appearance of the word is glossed ignis ossium — Latin for "fire of bones." A citation from the 15th century confirms that this may not be 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

“But in worship of Saint John, the people woke at home and made three types of fires. One was clean bones and no wood and that is called a bonefire…”

In medieval times ‘Bonefires’ were probably common towards the end of the agricultural year, when any farmer needing to eke out their winter fodder would slaughter some of their livestock, keeping only breeding pairs with a view to replacing their stock the following spring. Having preserved the meat, rendered the fat, and treated the hides, they were left with the carcasses – the bones. These were then burnt on “bone fires” so as to convert these otherwise useless bones into potash fertiliser… This winter tradition is probably one reason a bonfire is used to celebrate Guy Fawkes' Night in the UK, on 5th November each year.

There are a few key points in favour of the "bone fire" etymology:

  1. The French – English composite word idea is somewhat unusual.
  2. Knowing that the word goes back to the 15th century, it is more likely to have evolved into boonfire, since boon is the English form that developed from the French bon.
  3. The spelling in the word's earliest appearance is in the form banefyre, and bane is a spelling of bone which continued in common use in Scotland.

Solution 2:

People who teach languages well usually try to make the subject matter interesting and pertinent to the lives and interests of the students involved. So very young learners learn the names of animals and the sounds they make, for example, because that is something that very young people are usualy interested in, not because knowing ribbet is very useful when you become an international lawyer.

Another feature of good language teaching is often felt to be to engage the learners with the interesting or colourful aspects of the culture that the language is associated with. So students of English often know terms like Big Ben or even bowler hat, even though these items are not high frequency for real speakers of English.

Lastly, teachers often try to make their lessons topical for students. So we might expect lessons about Thanksgiving, Valentine's Day, Independence Day and so forth at relevant times of the year. No doubt next Friday, there will be thousands of lessons about the International Day of Peace.

The reason the Original Poster's son is learning the item bonfire during the first week in November is almost definitely related to the British cultural phenomenon of Bonfire Night, where we like to celebrate the fact that the Houses of Parliament only missed getting blown up by a gnat's whisker. How do we do this? We start fires up and down the country. Oops, I mean we have bonfires.

The problem with corpora like the BNC or COCA is that they cannot have a comprehensive coverage of different registers. So, for example you will find no hits at all for revise for an exam (rampant in British English) in either of these corpuses, even though hundreds of thousands of students of various descriptions commonly use this phrase. The spoken English of students is just not sampled when putting together such corpora.

So while the word bonfire might not feature heavily in the spoken English of international bankers or American news programmes, every November it has a starring role in the social calendar of every self-respecting British youngster along with other items such as sparkler, firework and toffee apple!