Translation guide
The English word 'infinite' describes something without limits or end. In Japanese, the concept is expressed through adjectives, nouns, and prefixes, with nuances ranging from mathematical infinity to poetic boundlessness.
Expressing that something has no boundaries, is endless, or immeasurable.
The most common and versatile word for 'infinite'. Can be used as a noun or adjective (with の or な). Suitable for both concrete and abstract contexts.
宇宙は無限に広がっている。
The universe extends infinitely.
彼の好奇心は無限だ。
His curiosity is infinite.
Literally 'endless', often used for vast expanses or long journeys. More literary or emotive than 無限.
果てしない砂漠を旅した。
We traveled across an endless desert.
Means 'unlimited' or 'boundless', often used for abstract qualities like love or potential.
限りない愛を感じる。
I feel infinite love.
Referring to the concept of infinity in mathematics, sets, or numbers.
Specifically means 'infinity' as a mathematical concept (e.g., the symbol ∞). Used in technical contexts.
この数列は無限大に発散する。
This sequence diverges to infinity.
Also used in mathematics, but 無限大 is more precise for the concept of infinity as a quantity.
Describing something that lasts forever, without end in time.
Means 'eternity' or 'eternal'. Focuses on endless time rather than boundless space or quantity.
永遠の命を求める。
They seek eternal life.
Also means 'eternal' or 'perpetual', but often used for things that are meant to last indefinitely (e.g., permanent structures).
Emphasizing an extremely large, uncountable number.
Means 'countless' or 'innumerable'. Used for things that are too many to count.
夜空には無数の星が輝いている。
Countless stars are shining in the night sky.
Using 'infinite' as an intensifier in compound words.
Prefix 無限 can be attached to nouns to mean 'infinite ~' or 'unlimited ~', e.g., 無限ループ (infinite loop), 無限の可能性 (infinite possibilities).
このゲームは無限ループに陥った。
This game got stuck in an infinite loop.
無限 (mugen) is the most general term for 'infinite', covering space, quantity, and abstract concepts. 永遠 (eien) specifically refers to infinite time or eternity, often with a poetic or philosophical nuance. 永久 (eikyuu) also means eternal but is more commonly used for permanent or long-lasting physical objects or states.
In casual English, 'infinite' is sometimes used hyperbolically (e.g., 'infinite patience'). In Japanese, using 無限 in such contexts can sound overly dramatic. Consider using とても (very) or すごく (extremely) instead, unless you want a poetic effect.
I study the theory of infinite sets.
永久に残る記録。
A record that will last forever.
Literally 'cannot finish counting'. A more colloquial way to say 'countless'.
数え切れないほどの思い出がある。
I have countless memories.