immuneyoudaoicibaDictYouDict[immune 词源字典]
immune: [15] The -mune of immune is the same as that of remunerate and of commune (and hence of common). It represents Latin mūnis ‘ready to give service’. The addition of the negative prefix in- gave immūnis, which in classical Latin denoted literally ‘exempt from a service, charge, etc’, and hence by metaphorical extension ‘free from something, devoid of something’. This general sense still survives, of course, in English (as in ‘grant immunity from prosecution’); and the more specific ‘not liable to infection’ did not emerge until as recently as the 1870s, probably under the influence of French or German.
=> common, commune, remunerate[immune etymology, immune origin, 英语词源]
immune (adj.)youdaoicibaDictYouDict
mid-15c., "free; exempt," back-formation from immunity. Latin immunis meant "exempt from public service, free from taxes." Specific modern medical sense of "exempt from a disease" (typically because of inoculation) is from 1881. Immune system attested by 1917.