'austerity' originates from Latin, specifically the word 'austeritas', where 'auster-' meant 'harsh' or 'severe'.

'austeritas' passed into Old French as 'austérité' and later into English (Middle/early Modern English) as 'austerity', becoming the modern word 'austerity'.

Initially it meant 'harshness' or 'severity'; over time it acquired additional senses such as 'stern simplicity' and, more recently (19th–20th c.), an economic sense referring to strict fiscal policies to reduce deficits.