'marketability' is formed in modern English from the noun 'market' + the adjective-forming suffix '-able' and the noun-forming suffix '-ity', indicating 'the quality of being able to be marketed'.

'market' comes into English from Old North French/Old French 'marché' (market, marketplace), ultimately from Latin 'mercatus' (trade, market) and the verb 'mercari'/'mercare' (to trade). The suffixes '-able' and '-ity' derive from Old French and Latin (e.g. Latin 'habilitas' via Old French 'abilite'). Over time these elements combined in Modern English to form 'marketable' and then 'marketability'.

Originally 'market' referred primarily to a physical marketplace or the act of trading; over time it broadened to include the commercial value or appeal of goods and services. 'Marketability' therefore evolved to mean the quality of being suitable or attractive for sale.