One of the new trends in modern encyclopedias is the key words. It used to be that you'd look at an encyclopedia and the spine would say something like bis-cen. Nowadays it will say something like impressionism - juggling. Not a big deal, but it can (on occasion) lead to hilarity.
Encyclopedia Britannica is currently following this trend – using key words as opposed to key groups of letters. Their Macropædia (knowledge in depth) has a volume about Excretion Geometry.
They put one word on one line and the second word on the next instead of using a dash. That’s totally fine with me, but don’t be surprised if I turn into a middle schooler and giggle like I think poop jokes are funny.