I don’t know whether you’ll find this word pretty, with its collection of five round letters and a tall, straight one. It has a certain prettiness of sound, at least in the opening: the aspiration on the /k/ spreads onto the /l/, devoicing it, making that voiceless liquid which seems so mystical and charming in Welsh (written ll), and with the stop at the beginning it is rather reminiscent of the voiceless lateral affricate famous in Tibetan (written lh as in Lhasa) and also present in Icelandic (written ll), among other languages.
It’s a word that seems to involve a relaxing effect, too: the unstopping at the beginning, the easing into the voice, the relaxation of the lip muscles from the tight ring at /o/ to the wider /æ/ and then the fully relaxed final vowel. It makes me think of Dulcolax, a brand name for a laxative that, the way they say it on their commercials, seems almost to have a laxative effect by itself.
And fitting that cloaca should seem laxative, just as it is fitting that it anagrams to lo, caca. Oh, its referent is something you will want to cloak (perhaps in a garderobe – which means “cloakroom” but in medieval times was also a word for an indoor outhouse, as it were). A cloaca, you see, is a waste canal. If cloaca sounds like it should be a kind of bird, well, it’s a kind of thing that birds (and monotremes, e.g., the platypus) have: a single excretory outlet, rather than the two that mammals have (known generally as “number one” and “number two”).
It’s also a kind of thing that cities have. Most cities don’t call their sewers cloacae, but the Romans did – why not? It’s their word, taken right from them, and derived in its turn from cluere, verb, “purge”. Rome had its Circus Maximus; it also had – and in fact still has – its Cloaca Maxima, running in a tunnel under its fora and letting out in the Tiber. (Now it just drains rain, but it was formerly a full-on sewer, and a big one.)
And it’s a kind of thing some art galleries have. Belgian artist Wim Delvoye has made several versions of a machine he calls Cloaca. It is “fed” a meal twice a day, and that is processed through a series of containers, which emulate the action of the human digestive system. At the end of it is a conveyor belt, which carries away what comes out of the end of the “digestive” system.
I suppose now would not be a good time to mention that cloaca also has echoes of chocolate, would it? I might be safer noting the hint of Coca-Cola. Well, anyway, I think we’ve gotten to the bottom of this word.