1Not easy to understand or accomplish; describes something complicated or troublesome, and can also describe a serious illness or problem.
漢字の読み方は外国人にとって難しい。
Reading kanji is difficult for foreigners.
この数学の問題は難しくて、何度もやり直した。
This math problem was difficult, so I redid it several times.
部長の病状は難しいと医者から聞いた。
I heard from the doctor that the manager's condition is serious.
初心者にとって、この操作は少し難しいかもしれない。
For beginners, this operation might be a little difficult.
2A softer, euphemistic way of saying something is nearly impossible or unfeasible — gentler than saying "muri" (no way).
明日までに直すのはさすがに難しいです。
Fixing it by tomorrow is honestly going to be difficult (basically impossible).
この予算で新しい機械を買うのは難しいですね。
Buying new machinery with this budget is going to be difficult.
来月の出張、参加は難しいと思います。
I don't think I'll be able to make it on next month's business trip.
3Used to describe a person or matter that is fussy, particular, or hard to satisfy due to strong preferences or demands.
彼は服の好みが難しくて、選ぶのに時間がかかる。
He's particular about his clothing preferences, so it takes time to choose.
あのお客様は注文が難しいことで有名だ。
That customer is famous for being difficult to please with orders.
難しい上司の下で働くのはつらい。
Working under a fussy boss is tough.
4Describes a dark or severe atmosphere or facial expression, often looking displeased or troubled.
社長は難しい顔で会議室に入ってきた。
The president walked into the meeting room with a grim expression.
何か難しい顔をしているけど、大丈夫？
You look kind of gloomy — are you okay?
5An archaic meaning of "dirty" or "unclean"; this sense is not used in modern Japanese.
6An archaic meaning of "unpleasant" or "creepy"; this sense is not used in modern Japanese.