RASM. رسم.
pl. Rusum. Lit. “That which is stamped or sealed. According to the Qur’an, but it is a very ancient word used in Arabia before the days of the Prophet for custom and law, the ancient records of the people being entitled Rawasim رواسيم, It me a word which is very common in Hindustan for the customs and usages of the people.

Based on Hughes, Dictionary of Islam