'salt-resistant' originates from English, specifically the words 'salt' and 'resistant'. 'salt' comes from Old English 'sælt' (from Proto-Germanic *saltą) meaning 'salt', and 'resistant' comes via French 'résistant' from Latin 'resistere' meaning 'to stand back/against'.

'salt' changed from the Old English word 'sælt' and eventually became the modern English word 'salt'. 'resistant' developed from Latin 'resistere' to Old French (résister) and Middle English 'resist', later forming the adjective 'resistant' in modern English; combined as the compound 'salt-resistant'.

Initially the components meant 'salt' and 'to stand against'; over time the compound came to mean 'able to withstand salt' (i.e., not harmed or corroded by salt), and this basic sense has been maintained in modern usage.