'assassin' originates from Arabic, specifically the word 'ḥashshāshīn' (or 'hashshashin'), where 'ḥashīsh' meant 'hashish' (cannabis) and the suffix indicated people (members of a group).

'assassin' changed from the Arabic word 'ḥashshāshīn' and was recorded in medieval Latin and Old French (as 'assassin'), then entered Middle English (as 'assassyn') and eventually became the modern English word 'assassin'.

Initially, it meant 'a member of a sect associated with hashish use', but over time it evolved into the modern meaning of 'a person who murders an important person (often for political reasons)'.