One of the best things about Soldiers' Songs and Slang of the Great War (apart from the fact that it is currently only £5.24/$9.71 as part of our 25%WWI discount!) is that for many of the entries it gives an etymological history of how a term came into being as well as a definition.
As well as this, it also reveals some words, or at least derivatives of those words, that we still use today. it is these that feature in the BBC History article, which can be read here.
Of the 10 slang words, one whose origins I was totally unaware was number five:
5.) Third Light
A superstition that it was bad luck to light a third cigarette from the same match. This was actually based on sound experience: it took a German sniper about five seconds at night to see, aim and fire at a light source, and a flaring match was clearly visible on a dark night from well over 500 yards. Five seconds was also about the time it took for the third man to light up.
Give the article a read through, and take advantage of our WWI discount to grab a copy of Soldier's Songs and Slang of the Great War before the month is out!