Imagine stepping onto the dance floor at a club and seeing a discobolus. How would you like that? I would not, even if the discobolus were covered with little mirrors. A discobolus is not a disco ball, you see, nor even a bolus in a disco. The stress is on the second syllable, rather like discover us: “Let’s hid behind the turntables; he won’t discobolus.”
The disco, to be sure, is the same disco as elsewhere, referring to discs – including the discus, and quoits (rings tossed like horseshoes). It comes from Greek diskos. The bolus is from Greek bolos, “thrower”, from ballein, “throw” (as in ballistic). The us ending tells us it’s come by way of Latin, as the equivalent Greek ending is os.
So a discobolus is a discus thrower. The c, o, and o are reminiscent of discs, anyway. The word starts on the tip of the tongue, swings back at /k/ to the velum, up to the lips at /b/, and then back to the tip (tip tip back lips tip tip – same rhythm as a popular hockey chant: “Let’s go, [two-syllable team name], let’s go!”). The movement is only vaguely reminiscent of the wind-up of a discus thrower.
So if there were a discobolus in the middle of the dance floor, he would truly be a diabolus in musica (and might be that way due to a diminished fifth – of Scotch, say). And if we were there dancing and he chose to hurl his discus or quoit, it would just clobber us. And would we be discombobulated? Quite.