Not yet but I have now! Thanks! 
Neat how todom(aru/eru) ends up meaning “stop” but todok(u/eru) ends up meaning “deliver” with that common semantic notion of a thing in motion entering a state of non-motion… or the other way around… almost a little too neat to be a coincidence…
(mmm… ancestor morphemes…)
It’s “kukarekuu” in Russian, not far from Dutch and German.
I know 酸素 - さんそ - oxygen for some time, but today I examined the kanji closely and was like, isn’t that the kanji for acid? Indeed, the kanji mean acid/sour and matter/material.
So where’s the mindblow in that one? It’s in the fact that the German word - Sauerstoff - also means sour + material. 
Ah, this. Japanese is my third languages, which English being second and Vietnamese the first. It was great when it came a sudden realization that “oh shit, I can think and read in English without having to translate it.” and I didn’t even know how or when did that first happened lol.
One thing that I’m trying to implement is that instead of trying to translate the vocab, I would try to imagine it instead. For example when I read the word 猫, I will usually imagine the cat itself instead of thinking about the word “cat”. Of course, this is gonna be hard with abstract vocab, so I guess it should come with practice. It’s a shame that I couldn’t remember exactly what I did to reach this level of proficiency in English. Perhaps having English-speaking friends that you can talk to contribute a lot.
Hey that’s so cool! We’re rooster-sound buddies!
I can’t find anything to back this up, but my gut feeling is that the どまる in とどまる couold a rendaku’d form of とまる (stop), just considering the similarity between them.
I should stress that this is entirely speculative; they could simply be cognates, or とまる could be a truncated form of とどまる, or any number of other explanations.
Still, I’m going to have to see if I can find any more info on these words.
Edit: After a bit of searching, it seems my “analysis” was probably too shallow. A first lead suggests the following theories:
とまる is cognate with to たまる, as in 溜まる (to accumulate) and 堪る (to refrain; to restrain oneself).
とどまる is cognate with ただよう, as in 漂う (to float; to drift; to hang in the air). Both involve staying mostly in place, but allows for small, mostly erratic movements (for example, a person staying in a house does not need to stand completely still).
More study is required! I look forward to improving my Japaneses to the point where I can really get into Japanese resources!
Today I read that the word for money exchange (両替) actually comes from the currency used in the Edo period - 両 (りょう).
I had never really questioned the origin of the word, so it was a cool realization.
Not the biggest one, but five seconds ago I was kind of hit with a realisation.
I just learnt the word caterpillar and one of the example sentence was about a green caterpillar.
We use something in our lab called midori green - we use it to stain our gel, so we can see if we have positive samples or not. If our supplier were nippongenetics, I think I’d have made the connection earlier that みどりsimply means “green”, and this product is essentially called “green green”.
Gonna have some fun with that tomorrow.
Small connection, I have played Yakuza Kiwami and I knew the second part stood for extreme. So I used this to connect to 極, which I just found out was the actual kanji that was used for it. So now I won’t forget that reading.
あたり まえ…of course
I had always thought that the word “hancho” originated from the Spanish language, just because it sounds so similar phonetically. So when I came across 班長 (はんちょう) in the vocab, I was pretty floored to say the least. The “squad leader” is the head hancho. I would have never guessed the reading to come from Japanese, especially having heard it a lot in an area with a high level of Spanish speakers.
They have identical meanings. 国 is a simplification of the Traditional Chinese 國, and Simplified Chinese uses the exact same character as in Japanese. Simplified Chinese showed up around the same time as the Japanese simplifications, so I’m not sure who came up with it first or if they were separate simplifications that just happened to look the same. However, I doubt that China would have adopted a character based off of the Japanese flag, especially post WWII.
What I thought was surprising is how similar Japanese meanings and readings are to Chinese. Quite a few Japanese words read and mean almost exactly the same in Chinese. Some examples are 安全 (Ānquán/anzen), 圖書館/図書館 (Túshū guǎn/toshokan), 颱風/台風 (Táifēng/taifuu). It’s made learning certain words a lot easier.
All the Onyomi come from Chinese, the question is just how much the pronunciation in China changed in 1500 years
It was recently pointed out to me that when 園 or 館 is used as a suffix on a word that has two kanji, the accent falls on the mora before the え or the か.
All of these words fit that pattern.
動物園
植物園
保育園
幼稚園
果樹園
映画館
博物館
美術館
大使館
図書館
領事館
An exception I found was 迎賓館, perhaps because it would be awkward to have an accent on an ん.
I don’t know if this is just an example of a larger rule related to suffixes, perhaps something explained in Dogen’s series, but these are mostly very common words so it’s helpful to me.
Guys
でも
で
も
I can barely believe it.
eyeball is 目玉
The reading of 拳 is こぶし, which can be thought of as a reading of 小武士 - “little warrior”.
I’m pretty sure this is not actual etymology and just mnemonic coincidence, but it’s a really easy way to remember the reading - I imagine a tough guy referring to his fist as his “little warrior”.
(Previous posting of this comment was accidentally a reply to a previous comment; couldn’t figure out how to edit it, so I deleted it…)
Guys 兄弟brothers is literally the kanjis for older brother and younger brother put together. Never knew this before it came up in a lesson.
One of the first words I learned in Japanese was やさい but I didn’t learn it’s kanji and I thought it sounded like kun’yomi until I learned it’s kanji recently.
Now that I think about it, the sound あい is pretty rare in kun’yomi if you don’t count いadjectives.
I have no evidence to back this up, but I don’t think the pitch can drop immediately after ん. It’s just something I’ve had a feeling about for a while, and searching through several dozen words on jisho hasn’t shown otherwise.