'acid-susceptible' is a compound of 'acid' and 'susceptible'. 'acid' originates from Latin, specifically the word 'acidus', where 'acidus' meant 'sour'. 'susceptible' originates from Latin, specifically the word 'susceptibilis', from 'suscipere' ('sus-' + 'capere'), where 'suscipere' meant 'to take up' or 'to receive.'

'acid' passed into Old French as 'acide' and then into modern English as 'acid'. 'susceptibilis' passed into French as 'susceptible' and then into English as 'susceptible'; the compound 'acid-susceptible' is a modern English formation combining the two terms.

Individually, 'acid' originally meant 'sour' and 'susceptible' originally meant 'able to be taken or affected'; combined in modern English the compound came to mean 'able to be affected or attacked by acid' (vulnerable to acid).