also: ろうちょう
noun
man aged 61–65 (ritsuryō system)
Historical term from the ritsuryō legal codes; refers to a man in the 61–65 age bracket for corvée and tax purposes.
律令制では、老丁は課役の一部が免除された。
Under the ritsuryō system, men aged 61–65 were exempt from some corvée duties.
From 老 (old) + 丁 (adult male in the ritsuryō labor system). The exact historical derivation is uncertain, but the term is firmly associated with the ritsuryō age-grade system.