'excusable' originates from Latin, specifically the word 'excusabilis,' where 'ex-' meant 'out of' and 'causa' meant 'cause or reason.'

'excusabilis' transformed into the Old French word 'excusabel,' and eventually became the modern English word 'excusable' through Middle English.

Initially, it meant 'able to be excused or justified,' and this meaning has largely remained the same in modern usage.