also: とうせい
noun
Archaic term for tattooing, especially as a form of punishment or marking. In modern Japanese, 入れ墨 (いれずみ) or タトゥー are used instead.
江戸時代には、罪人に箚青を施すことがあった。
In the Edo period, tattooing was sometimes applied to criminals.
「箚青」は、現代ではほとんど
箚青 is an old word that is hardly used today.
The exact derivation is uncertain. The kanji 箚 is rare and may be related to 'prick' or 'stab', while 青 refers to the blue/black ink used. The reading さっせい is likely a Sino-Japanese reading of the characters.