difference; discrepancy; (math.) difference (amount remaining after a
Depicts grain (來) being rolled between the fingers in the left hand (左). Based on the original meaning "rub between fingers", now written as 搓. The meaning later shifted to "uneven" and "error".
《說文》：“差，貳也，差不相值也。从左，从。二，籀文从二。”
rub between fingers