中学校時代のあだ名「酸化銀」の由来
B1 Japanese listening practice · Standard Japanese · Curated for intermediate learners
Why was the nickname “酸化銀” a chin joke?
In this clip, a man explains a nickname he was stuck with in junior high because of his protruding chin. Classmates in chemistry class were memorizing 酸化銀 (silver oxide), written by its formula “Ag₂O.” Drop the “2” and you’re left with the letters “AgO” — read straight through, that sounds exactly like あご (ago), the Japanese word for “chin” or “jaw.” A coincidence from an unrelated subject turned into a nickname that stuck for years.
Silver oxide really is Ag₂O in chemistry, a compound used in batteries and glass polishing, so the pun only works because Japanese students learn element symbols in katakana (“エージー,” “オー”) right alongside the Roman letters, making “AgO” legible as a word rather than just a formula. This kind of dajare (駄洒落, pun-based wordplay) nickname culture is common in Japanese schools, where a classmate’s appearance, name, or even a stray homophone from an unrelated class can become a lasting あだ名 (nickname).