'non-salt-tolerant' originates from Modern English as a compound formed by the prefix 'non-' (meaning 'not') + 'salt' + 'tolerant', where 'non-' meant 'not'.

'tolerant' originates from Latin, specifically the word 'tolerant-' (present participle of 'tolerare'), which passed into Old French and Middle English and eventually became the modern English 'tolerant'. 'salt' comes from Old English 'sealt' and Proto-Germanic '*saltą'.

Initially, components had basic senses ('non-' = 'not', 'salt' = 'salt', 'tolerant' = 'able to bear'), and their combination has retained a transparent modern meaning: 'not able to bear salt' (i.e., 'not tolerant of salt').