Yup, very useful word; I heard it quite a lot when I was in Japan.
It’s sometimes cited as an example of false friends in Japanese and Chinese (that is, words that are superficially similar but mean quite different things):
Japanese: “OK; out of danger; affirmative”
Chinese (Mandarin): “a gentleman; a man’s man; a man of character”
The Japanese word presumably had the same meaning as the Chinese word at some point, but as time went by the two meanings diverged. However, the origin of the phrase are still clear to see:
大 - big, grand
丈 - length, height, stature
夫 - husband, man
According to Wiktionary, the word has later been borrowed back into Chinese as internet slang for “OK”.
As for my latest words:
I was listening to an episode of ひいきびいき about IKEA.
Early in the episode, they mention:
I could more or less guess what はっしょう meant (being pretty スウェーデンはっしょう myself and therefore considering it my patriotic duty to be well-versed in IKEA:n lore), but I still felt I should look it up, so I typed はっしょう and then selected the first suggestion from the IME dropdown list.
発症 (はっしょう) - outbreak of an illness; onset of an illness; outbreak of symptoms
That’s right, everybody: IKEA is an illness that started in Sweden, but which has since become a pandemic.
Of course, the word they were using was actually:
発祥 (はっしょう) - origin; appearance of an auspicious omen
So, now I know both 発症 and 発祥! They both describe the onset of something, but one involves a foot wrapped in sickness and the other a spirit sheep that brings tidings of joy.