The lokadhātavaḥ (singular: lokadhātu) are often presented in English language Buddhist terminology as the “world-systems”, the (often infinite) totality of which is the multiverse-esque cosmology of some Buddhisms.
In the translations hosted here, lokadhātu is rendered as “solar system” in, for example, AN1.278-286 Dutiyavagga. This rendering is effective because it immediately brings to mind the notion of something “out in space”, and a “world”, and is a down-to-earth and reasonable sounding “modern” word for something “out there”. It doesn’t seem as “out there” as for instance if one were to call them “dimensions” or something like that, although I can certainly imagine reasons why a rendering like that would appeal to some people.
Keeping in mind a particular usage of dhātu that came up here:
I would like to take a moment to look at one particular usage of the word dhātu, although one cannot necessarily intuit the meaning of a word as it features in a compound from how it behaves alone. The word dhātu in the sense of “bits” of something. Like what is in the dhātugarbha, or “relic chamber”, which is a modern Hindi word with Sanskrit roots.
It seems that in most Buddhisms, these are actually called śarīrāḥ. The Buddhists communities that produced the various Mahāyāna Parinirvāṇa vaipulya sūtrāṇi calling them “dhātavaḥ” seem to be part of a minority practice in as far as referring to these things by a different name.
In addition to this visual notion of a dhatu as a “bit” of something, I would also like to take in account this definition of the word from Monier Williams’s 1899 A Sanskrit–English Dictionary at page 513 which is wonderfully available to us via Wiktionary:
धातु • (dhātu) m
- layer, stratum
- constituent part, ingredient
It is the “constituent part” meaning. A “bit” of something in the sense of a “[tiny] part [of it]”.
We uncontroversially render “loka” as “world” generally. I don’t think anything has ever thought up a better term for it.
With no more bluster I would like to offer my suggestion for an English language rendering of the word lokadhātu. I don’t actually consider myself qualified to make any kind of authoritative suggestions (and who would?) with regards to if this is better or worse than any other people’s renderings.
Here it is, and I hope that Ven @sujato won’t mind me butchering his translations to provide examples:
a place in the world
It is impossible, mendicants, it cannot happen for two wheel-turning monarchs to arise in the same place in the world at the same time.
IMO very simple, very literal. It has the sense of “worldpiece” without the Germanic-sounding coinage. We don’t really say
a piece of the world
It is impossible, mendicants, it cannot happen for two wheel-turning monarchs to arise in the same piece of the world at the same time.
although that would be an even better rendering IMO. Trying to preserve the very generalized sense of “piece” we have the option of
a piece of the cosmos
It is impossible, mendicants, it cannot happen for two wheel-turning monarchs to arise in the piece of the cosmos at the same time.
So there’s my suggestion. If I ever took to translation seriously, I think that is where my reasoning would lead me.
Perhaps it is bad reasoning!