老い|おいoi[0]heiban (flat)

1. no-adjectiveold age; ageing; aging
   少年しょうねん老おい易やすく学がく成なり難がたし。↗

   Art is long, time is fleeting.
2. nounold person; the elderly; the aged

• Synonym老齢ろうれいNeutralRefers to advanced age, as in 「老齢年金」; an institutional term that leans formal.
• Synonym老年ろうねんNeutralRefers to the old-age stage of life, as in 「老年期」; it treats ageing as a life stage.
• Synonym高齢者こうれいしゃNeutralRefers to elderly people, typical of administration and welfare, as in 「高齢者施設」; neutral and formal.
• Synonym老いらくおいらくWrittenAn archaic, literary way to say old age, seen mostly in 「老いらくの恋」.
• Synonym老年期ろうねんきWrittenNames the old-age stage in human development; a psychological, academic term.
• Related年寄りとしよりNeutralRefers to elderly people, common in speech as 「お年寄り」; it names the person, whereas 「老い」 is the ageing itself.
• Related年老としおいWrittenA written word for an aged person; examples are scarce.
• Related老人ろうじんNeutralRefers to old people, as in 「老人ホーム」; a person word with an objective tone.
• Related古老ころうWrittenA written term for an elder well versed in the distant past; little used today.
• Related高齢こうれいNeutralMeans advanced age, as in 「高齢化社会」; statistical and formal, without the pathos of decline.
• Related長老ちょうろうNeutralA venerable elder or a senior temple monk; carries respect.
• Related老ろうNeutralServes as a prefix or suffix meaning old, as in 「老夫婦」 and 「敬老」; rarely used alone.
• Related老骨ろうこつWrittenA humble way to speak of one's own aged body, as in 「老骨に鞭打つ」; self-deprecating.
• Related老体ろうたいWrittenAn aged body or an old person, often in the respectful form 「ご老体」.
• Related老輩ろうはいWrittenA written word for the older generation, or an old person's humble self-reference; rare today.
• Antonym若さわかさNeutralYouth and vigor — the direct opposite of 「老い」.

Use 「老い」 for growing old and for the decline of body and mind itself. For advanced age in formal or statistical contexts choose 「高齢」 or 「老齢」; for the life stage, 「老年」. When speaking of elderly people, 「お年寄り」 and 「高齢者」 are the everyday and official choices. 「若さ」 is the opposite: youth.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 年としを取とること。老化ろうか。