Questioning correspondent B.W. is looking for a Japanese word meaning "a bad habit" and which he recalls as possibly tsudoku.

Neither my memory nor dictionary contain such a word, nor anything really close. (There's tsuudoku つうどく 通読, meaning to "read through [thoroughly]", but that's not it.)

My guess is that the word being sought is chuudoku ちゅうどく 中毒, which is "poisoning" or "addiction". The latter meaning might include that idea of "bad habit". Read more about What's that word?: Chuudoku (poisoning / addiction)

Hey, how'd I let this one go untouched for so long? Of all the misconceptions about the Japanese language, "three writing systems" has got to be the most widespread, even among people who really should know better.

Know how you'll sometimes see a definition of a foreign-language word that just seems to pack way too much meaning into that single bite? Like this, from the Kara people of the Omo valley in Africa, as reported by the March 2010 National Geographic:

The name of the village – Dus – means, roughly, "I have seen other places, but it is good here. I'll stay."

Wow. Now that's efficient! Read more about Now that's a mouthful

Back in 2005, Japan Times science writer Rowan Hooper noted US-based medical studies which, although inconclusive, suggested that aging-related conditions could be ameliorated through transcendental meditation (TM) techniques such as mindfulness and progressive muscle relaxation. Hooper went on to suggest that Japanese lifespans may be long due to similar effects brought about by two factors: Buddhism and "shikata ga nai mentality". Read more about Debunked: The uniquely Japanese "shou ga nai"

A single word for "death from overwork" – imagine that! You've probably seen the astonishment over that fact in contexts like this WIRED article: "And in a nation that actually has a word for 'death from overwork,'...", the gist of which is that the existence of a single word for the concept reveals its unusual severity or significance in Japan. 

In fact, there is a single word for "death from overwork" in Japanese: karoushi (過労死). There's no argument about that (well, except maybe from those claiming that Japanese has no words). The word exists.

What I'm debunking here is the overworked meme that the phenomenon's single-word status has any significance whatsoever. It doesn't. Read more about Debunked: "OMG Japanese has a single word for 'death by overwork' "!