'forfeitability' originates from English, formed by combining 'forfeit' with the suffix '-ability', where 'forfeit' means 'to lose or give up as a penalty' and '-ability' denotes 'the quality of being able to'.

'forfeitability' was created in modern English by adding the suffix '-ability' to 'forfeit', following the pattern of forming nouns indicating a state or quality.

Initially, it meant 'the quality of being forfeitable', and this meaning has remained consistent in modern usage.