noun, adverb
Physical or spatial interior; also used for abstract boundaries like time limits or ranges.
箱の内に手紙が入っている。
There is a letter inside the box.
一時間の内に終わらせます。
I'll finish it within an hour.
noun, adverb
while; during; in the course of
Temporal use: marks a period or state during which something happens. Often written in kana.
若いうちにいろいろな経験をしたほうがいい。
You should have various experiences while you are young.
明るいうちに帰りましょう。
Let's go home while it's still light.
noun, adverb
Used in the pattern 〜のうち to indicate selection or comparison within a group. Usually written in kana.
この三つのうち、どれが一番好きですか。
Which do you like best among these three?
友達のうちで彼が一番背が高い。
He is the tallest among my friends.
noun
in (a state); amidst; with
Pattern 〜のうちに after a noun representing a state or condition: in secret, in chaos, with success, etc. Also written 裡 or 裏 in literary contexts. Usually written in kana.
成功のうちにプロジェクトを終えた。
We completed the project with success.
混乱のうちに会議が始まった。
The meeting began amidst confusion.
noun
within oneself; one's inner thoughts
Refers to one's inner feelings, thoughts, or heart. Often used in expressions like 心の内 or 胸の内.
彼は心の内をなかなか見せない。
He rarely shows his inner thoughts.
胸の内を打ち明けた。
I opened up about my feelings.
noun
we; our company; our organization
Only when written 内
Humble first-person plural used in business or formal contexts to refer to one's own group. Antonym: そと (outside group). Usually written in kana.
内ではそのように決まっております。
That is what we have decided within our company.
内の者に確認します。
I will check with someone from our organization.
noun
Only when written 内
Refers to one's own home or family. Also written 家. Usually written in kana in modern usage.
See also: 家 (うち)
今日はうちでゆっくりします。
I'll relax at home today.
うちの家族はみんな犬が好きです。
Everyone in my family likes dogs.
noun
my spouse; my husband; my wife
Only when written 内
Humble reference to one's own spouse. Gender-neutral but context-dependent.
うちの主人は今出かけております。
My husband is out right now.
うちの妻がお世話になりました。
My wife has been in your care.
noun
signed on behalf of husband by wife
Only when written 内
Archaic epistolary convention: wife signs a letter after the husband's name using 内. Very rare in modern Japanese.
古い手紙の末尾に「太郎 内」と書かれている。
At the end of the old letter, it says 'Tarō uchi', meaning signed by his wife on his behalf.
pronoun
Only when written 内
Kansai dialect first-person pronoun, primarily used by women and children. Casual and regional.
うち、そんなん知らんわ。
I don't know anything about that. (Kansai dialect)
noun
imperial palace grounds; emperor
Only when written 内
Archaic. Refers to the imperial palace or, by extension, the emperor. Not used in modern Japanese outside historical contexts.
内裏の内は一般の者は立ち入れなかった。
Commoners were not allowed inside the imperial palace grounds.
Search-only form; used in the sense of 'amidst' or 'in a state of'.
Search-only form; used in the sense of 'amidst' or 'in a state of'.
Rare alternate kanji; 内 is overwhelmingly preferred.
中 (なか) also means 'inside', but is more concrete and physical. 内 (うち) often has abstract, temporal, or in-group nuances.
内部 is a formal term for 'interior' or 'inside', often used in technical or organizational contexts, while 内 is more versatile and colloquial.
家 (いえ) refers to a physical house or building; 内 (うち) refers to one's home as a personal, familial space.
The historical derivation is uncertain. The kanji 内 is conventionally associated with the meaning 'inside' and has been used for this word since Old Japanese.