also: しゃくどく
noun
A formal, literary term for a letter or epistle, derived from classical Chinese. Extremely rare in modern Japanese; used mainly in historical or literary contexts. The more common modern word is 手紙 (てがみ).
尺牘という言葉は、昔の手紙を指す雅語だ。
The word 尺牘 is an elegant term for old-fashioned letters.
彼は尺牘の名手として知られていた。
He was known as a master of letter writing (using the classical term 尺牘).
From Chinese 尺牘 (chǐdú), literally 'foot-long wooden tablet', referring to the writing medium for letters in ancient China. The Japanese readings are on'yomi.