So… yes and no. ぢ and じ I believe used to sound different, but in modern speech they’re pronounced exactly the same (edit: well, usually - see Kumirei’s post below).
Within the context of 地, I would think that じ isn’t really a separate reading, but instead a modern simplification of ぢ. Though technically I guess I don’t know that with certainty. edit: seems like I’m likely wrong about that too lol - じ is its own on’yomi, separate from ち
It’s not Rendaku, because rendaku is a Japanese philological thing.
Both ち and じ are on yomi according to Jisho online. So this is a matter of when the word was adopted from Chinese. One approximates an older Chinese pronunciation, and one a newer.
I need to read more about it because I’m still reading it as renderku in my mind: a rendered sound. It makes zero sense but my brain is doing it by itself. Bad, bad brain.
Philological means related to the development of languages. I’m not sure I’m using it correctly… but the gist is, rendaku is the result of Japanese speakers changing their own consonant sounds over time. 地’s two readings were the result Chinese speakers changing their pronunciation of 地 over time (or different dialects). It’s the same philological process, probably, but only when in occurs in Japan does it count as Rendaku.
My apologies, I misread this. Someone mentioned that thing about reading only the first and last letter of a word and guessing the rest in another post today: I did just that.
I guess I should also add that Yotsugana doesn’t count as Rendaku either, even though it is philologically the same process of consonant shifts that happen universally in all languages. Rendaku is only when you add the two dots.
Though 年中 (ねんじゅう) according to WK is rendaku, but you would expect ねんぢゅう… I think the former is an alternate modern spelling, and the latter is the “historic” spelling. And this looks like the alley situation, but it’s not. It just looks like it!
Meow, in case you haven’t seen this link yet, I feel it explains it pretty well, even if the bottom line is that no rule is going to give you 100% accuracy to figure out rendaku.
We discussed the possible origins of Rendaku in my Japanese Linguistics class first semester. The theory I remember is that a lot of words that now have Rendaku used to have の in them. If we use sea turtle as an example, we assume with this theory it started as うみのかめ uminokame. Over time, people stopped pronouncing the [o] and our example changed to uminkame. That in turn changed to a [ng] sound, so umingame. That [ng] then morphed into the first consonant of the second word becoming voiced, so for sea turtle ウミガメ umigame. If I recall correctly, the last part of the theory is supported by some modern pronunciations that interchange ng/g at the beginning of words. Maybe in the Tokyo dialect?