Translation guide
The English word "solid" has several distinct meanings. This guide organizes them by practical use, from physical states to abstract qualities, and provides natural Japanese equivalents for each.
Describing matter that is firm and stable in shape, not a liquid or gas.
The standard scientific/technical term for 'solid' as a state of matter. Used in formal contexts.
水は液体で、氷は固体です。
Water is a liquid, and ice is a solid.
Often used for 'solid' as opposed to liquid or powdered forms, e.g., solid food, solid fuel.
固形燃料はキャンプで便利です。
Solid fuel is convenient for camping.
General word for 'hard' or 'firm'. Can describe a solid object, but not the state of matter itself. Use with care: 固い means 'hard', not necessarily 'solid'.
Not a direct translation for 'solid' as a state; it means 'hard' or 'stiff'.
このパンは固い。
This bread is hard.
Describing an object that is strong, dense, and not easily broken or deformed.
Describes something sturdy, solidly built, durable. Common for furniture, buildings, vehicles.
この机は頑丈で長持ちしそうです。
This desk is solid and seems like it will last a long time.
Means 'solid', 'firm', 'steady'. Very common for describing construction, handshakes, arguments, etc.
しっかりした作りの家ですね。
This house has a solid construction, doesn't it?
Formal/literary term for 'solid', 'firm', 'strong'. Often used for defenses, structures.
堅固な要塞だった。
It was a solid fortress.
Describing something that is not interrupted, such as a solid line, solid color, or solid hour.
Specifically a 'solid line' as opposed to a dashed or dotted line.
実線の内側に停めてください。
Please park inside the solid line.
Describes a solid color with no pattern. 'Solid blue' = 無地の青.
無地の赤いTシャツを探しています。
I'm looking for a solid red T-shirt.
Used before time words to mean 'a full/solid' amount of time. E.g., まるまる1時間 (a solid hour).
Means 'continuous', 'consecutive'. Can be used for solid blocks of time or unbroken stretches.
連続した3時間の会議だった。
It was a solid three-hour meeting.
Describing a person or thing that is trustworthy, sensible, and consistently good.
Means 'reliable', 'trustworthy'. The most direct equivalent for a solid person.
彼は信頼できる人物だ。
He is a solid person.
Means 'solid', 'steady', 'sound'. Often used for people, businesses, plans.
堅実な計画を立てましょう。
Let's make a solid plan.
A noun meaning 'a reliable/solid person'. Often used in casual praise.
Describing something that is well-made, substantial, or satisfactory. Often used in phrases like 'solid meal' or 'solid performance'.
Again, very versatile. A 'solid meal' can be しっかりした食事.
朝はしっかりした食事をとりなさい。
Eat a solid breakfast.
Means 'fulfilling', 'substantial'. Good for 'solid experience' or 'solid content'.
充実した一日だった。
It was a solid day.
Means 'splendid', 'fine', 'solid'. Can be used for a solid achievement or performance.
立派な成績だ。
That's a solid result.
Describing a group that is fully united in opinion or support.
Means 'united', 'in solid support'. Often used for teams or groups.
チームは一致団結して優勝を目指した。
The team was solid in their aim for the championship.
Means 'unanimously'. Used in formal voting contexts.
その案は満場一致で可決された。
The proposal was passed with solid support.
Describing a geometric solid, a 3D object.
The standard term for a three-dimensional solid in geometry.
立方体は立体の一種です。
A cube is a type of solid.
The Japanese word 固い (katai) means 'hard' or 'stiff', not 'solid' in most senses. Using it for a 'solid plan' or 'solid person' would be unnatural. Use the specific equivalents provided for each meaning.
固い計画
a hard plan (unnatural)
まるまる一日かかった。
It took a solid day.
She's a solid person, isn't she?