Try to explain something while only using the thousand most common words in English. It’s harder than you might think. This comic from xkcd points out the difficulty in describing a space ship called the Up Goer Five, and an Up-Goer Five Text Editor...
day soldier n.— «But they will continue to provide insurgents, I’m sure. What has to happen here is to drive a wedge between the extremist leadership and what I call the “day soldiers,” [insurgents] those who sign up not because they are ideologues...
