'assignat' originates from French, specifically the word 'assignat' (a noun formed during the Revolutionary period), ultimately from the verb 'assigner' meaning 'to assign' or 'to allot'. The underlying Latin root is 'assignare' (ad- + signare).

'assignat' was coined in late 18th-century French for notes assigned to confiscated properties; English borrowed the term directly from French during and after the French Revolution to refer to those paper notes, and it entered English usage in the same form 'assignat'.

Initially connected with the idea of an 'assignment' or an instrument tied to assigned (confiscated) land, the term came to denote specifically the paper money (notes) issued by the Revolutionary government and later the concept of such inflation-prone currency.