高齢|こうれいkourei[0]heiban (flat)

1. no-adjectiveadvanced age; old age
   海うみがめは高齢こうれいまで生いきる。↗

   Turtles live to a great age.

• Synonym老年ろうねんWrittenThe stage of old age, with a written flavor, as in 「老年医学」.
• Synonym老齢ろうれいWrittenOld age, chiefly an administrative term, as in 「老齢年金」.
• Related老いおいWrittenOld age or the ageing process, literary and written in flavor, as in 「老いを感じる」; 「高齢」 is more formal and neutral, common in statistics and administration.
• Related老年期ろうねんきWrittenThe period of old age that follows middle age; common in medicine, nursing and welfare. 「高齢」 simply describes advanced age.
• Related老いらくおいらくWrittenThe declining years, with a literary flavor; rarely used in modern Japanese.
• Antonym若年じゃくねんWrittenYouth, the direct opposite of 「高齢」, as in 「若年層」.

Use 「高齢」 for advanced age, as in 「高齢者」 and 「高齢化」. For old age in a literary sense pick 「老い」; for the old-age stage, 「老年」 or 「老年期」; for administrative contexts, 「老齢」; 「老いらく」 is a rare literary word for declining years; 「若年」 is the opposite, for youth.

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

1. 年齢ねんれいが相対的そうたいてきに高たかいこと。
2. 年老としおいた状態じょうたい。