Does this word look threatening, even frightening? It does to my eyes; the rhabd in particular seems like something worse than rabid, worse than a raptor. It can’t simply be the rh; that shows up quite happily in rhetoric, rhapsody, rhyme, rhythm… I think it really is the grabbing of the /æbd/ after the quick growl of the /r/. The length of the word is also daunting, along with its two y’s like the extended claw feet of a raptor coming down to snatch you – or like drains to suck you down.
But undoubtedly it’s also because of what it signifies. After all, rhabdomancy manages not to be quite so nasty, though it is a bit of a hairy word for what is more calmly called dowsing. You know, when you use rods to tell you where the water (or sometimes other liquids) are. Now, you may well know that mancy is the part that refers to divination (as in cartomancy, necromancy, etc.). It thus follows that rhabdo means “rod”. Which it does. It’s from ῥάβδος rhabdos “rod” (you see that the ‘ over the rho means it gets “rough voicing,” which is represented in our spelling as the h after the r – and is resolutely ignored by us in pronunciation).
We can thus set aside any relation to abdomen – well, any etymological relation, anyway. But what about the myolysis? Some of you may recognize myo from words such as myocardial and myoelectric. It’s from μῦς mus “mouse, mussel, muscle” (yes, all three) and, in English words, refers to muscles. And lysis? It shows up in words such as electrolysis and is also present, mutatis mutandis, in words such as catalytic; it comes from λύσις lusis “loosening, parting” and refers to breakdown, decomposition, disintegration, dissolution.
So: rod, muscle, breakdown. No, it does not mean breaking down muscles by beating them with rods; although it may look like a name fit for a torture technique, we may spare those rods. Oh, being beaten with rods may lead to rhabdomyolysis. But the rods in this word are the muscle fibres. The word is not rhabdo+myolysis but rhabdomyo+lysis: breakdown of striped muscle.
It’s actually even worse than it sounds. If muscle is damaged enough to start breaking down – and this can happen through quite a lot of different causes, not just injury or overexertion but metabolic imbalances, infections, poisons, and even drug side effects – the products of the breakdown go into your bloodstream and can cause electrolyte imbalance (leading to confusion, nausea, coma, etc.) and kidney damage (possibly leading to death, etc.).
News reports on the cholesterol drug Baycol, which was taken off the market after it was associated with risk of rhabdomyolysis, sometimes described it as “muscle liquefaction” or words to that effect. That’s not exactly it, but the broken-down muscle passes into the bodily fluids (a notable sign is very dark urine), so “dissolution,” anyway, is not altogether inaccurate.
And how, by the way, do you say it? It’s tempting to give it a nice three-beat trochaic rhythm, like confutatis maledictis without the dictis. But actually it follows the grand old tradition of accenting Greek-derived words on the antepenult (the third-last syllable), making it a pair of dactyls. Pterodactyls? Eeks – that’s even worse than raptors.