Introduction
In English, the word "right" has several meanings. For example, it can be used to show a "direction," or it can be used to mean "legal entitlement." In addition, "light" can be about "brightness" or about "physical weight." Even if a word has more than one meaning, we can instantly determine which meaning it is referring to by context and by the course of the conversation.
Just as in English, there are words in Japanese that have multiple meanings. Today, I would like to introduce several examples of words that can have several meanings.
うまい (umai)
① Delicious
【Example】ここの酒はうまい。(Koko-no sake-wa umai)
【Meaning】The alcohol/liquor here is delicious.
② To be good at something.
【Example】絵がうまいね。(E-ga umai-ne)
【Meaning】You're really good at drawing.
③ Convenient
【Example】うまい話には気をつけたほうがいい。(Umai hanashi-niwa ki-wo tuketahō-ga ii)
【Meaning】You should be careful with stories that are too good.
It is often said that "every good story has a down side that is hidden." This means that if someone offers you a story that is almost too good to believe, there is always a downside to it that might not be as visible. The "hidden/behind" here refers to undisclosed internal circumstances. Be careful not to be deceived by a clever story that claims "anyone can easily get a large sum of money by just doing this!"
甘い (amai)
① To taste sweet like sugar or honey.
【Example】甘いお菓子が大好きです。(Amai okashi-ga suki-desu)
【Meaning】I love sweet desserts.
② Lacking strictness.
【Example】子どもに甘い親が多い。(Kodomo-ni amai oya-ga ōi)
【Meaning】Many parents are too easy on their children.
③ Taking it too easy and not being well prepared.
【Example】考えが甘い。(Kangae-ga amai)
【Meaning】Your thinking is too naive.
You probably already know what the first sentence means. The English word "sweet" can be used for both "taste" and "character." However, while "sweet" in English can mean "gentle and kind" when used to describe a person's personality, the Japanese word "甘い" can have a slightly negative meaning, such as "too/overly gentle" when used to describe a person, so be careful when using it.
熱い (atsui)
① Something is physically hot
【Example】熱いお茶が飲みたい。(Atsui ocha-ga nomitai)
【Meaning】I want a cup of hot tea.
② Intense emotions, heated, inflamed
【Example】私たちは政治について熱く語り合った。(Watashitachi-wa seiji-ni tsuite atsuku katari atta)
【Meaning】We had a heated discussion about politics.
③ Popular and trendy. Have received public interest.
【Example】今、AI業界がアツい。(Ima, AI gyōkai-ga atsui)
【Meaning】The AI industry is booming right now.
The meaning of ③ is used especially by young people and is often written in katakana as "アツい." In addition to "熱い" there is also "暑い" and "厚い" which all have the same pronunciation but different nuances/meanings in kanji. "暑い" is used for the temperature, while "厚い" is used to describe the thickness of something like a book or dictionary. Watch out not to use the wrong kanji when typing!
痛い (itai)
① Physical or emotional pain/distress
【Example】虫歯が痛い。(Mushiba-ga itai)
【Meaning】My cavity hurts.
② Having trouble dealing with something or receiving damage on a weak point.
【Example】この時期に1万円の出費は痛い。(Kono jiki-ni ichimanen-no syuppi-wa itai)
【Meaning】Having to shell out 10,000 yen during this time of year was a financial blow.
③ When someone's comments/actions are out of place and embarrassing. Someone's behavior/comments that are inappropriate for the situation, their position or age, which makes people around that person feel uncomfortable.
【Example】ぶりっ子の先輩、イタいわー。(Burikko-no senpai, itaiwā)
【Meaning】My senior (senpai) putting on a cutesy act is so cringe.
The last example is used especially by younger generations and is often written in katakana as "イタい."
くどい (kudoi)
① A dish being strongly seasoned
【Example】このラーメンはくどいから好きじゃない。(Kono rāmen-wa kudoi-kara suki-jyanai)
【Meaning】I don't like this ramen because it's too strongly seasoned.
② Saying the same thing over and over again and making others sick of it.
【Example】母は話がくどい。(Haha-wa hanashi-ga kudoi)
【Meaning】My mother always rambles on and on.
Both examples are used in a negative sense, and are often used to make a negative evaluation. When something is too greasy or seasoned too strongly, you can say that the dish is "くどい." You can also use "くどい" when the same words or actions are repeated so often that it becomes annoying. Both seasoning and words/actions are frowned upon if they are too "くどい," so watch out!
滑る (suberu)
① The ground or floor is wet and is unsteady. To slip.
【Example】雨で床が滑りやすくなっています。ご注意ください。(Ame-de yuka-ga suberiyasuku-natteimasu)
【Meaning】The floor is slippery due to rain, so please be careful.
② Fail an exam. Fail to pass.
【Example】第一志望の大学に滑る。(Daiichi shibō-no daigaku-ni suberu)
【Meaning】Fail the college entrance exam of your first choice.
③ Trying to say something funny but failing. A state of not being able to laugh.
【Example】話がスベって、気まずい雰囲気になった。(Hanashi-ga subette, kimazui fun-iki-ni natta)
【Meaning】The joke wasn't funny which caused the atmosphere to become awkward.
As you can see from the meaning in ②, "すべる" is considered bad luck for students taking an entrance exam. Other expressions such as "落ちる (ochiru; to fall)" and "転ぶ (korobu; to tumble)" are also considered bad luck because they are associated with failure. Be careful not to accidentally use these terms in front of a student preparing for their exam! The meaning in ③ is often used on TV by comedians. When used in this sense, it is often written in katakana as "スベる."
波 (nami)
① The rise or fall of the surface of the water in a sea or river due to wind, and other natural forces.
【Example】今日は波が高い。(Kyō-wa nami-ga takai)
【Meaning】The waves are high today.
② Having highs and lows, good and bad, or that something isn't constant.
【Example】前回のテストはよかったのに、今回は全然ダメだった。成績に波がある。(Zenkai-no tesuto-wa yokattanoni, konkai-wa zenzen dame-datta. Seiseki-ni nami-ga aru)
【Meaning】My score on the previous test was good, but it was not so good this time. My grades aren't stable.
Both ① and ② have the same underlying meaning (both express something going higher or lower), so I think it is fairly easy to imagine what they mean. The meaning from ② is used not only for school grades, but also for things that go up and down, such as a person's mood, emotions, and even the economy.
Summary
So, what did you think? Many of you have probably already heard of one of these meanings, but did not know about the others. There are many other words that have more than one meaning. If you look up Japanese words in a dictionary, you may find meanings and usages that you haven't heard of yet. By studying this way, you can further develop your vocabulary and expressions from the words that you already know!