IPA: //ʌn.səˈsɛp.tə.bəl//
KK: /ʌnˈsʌsɛptəbl/
Not able to be affected or influenced by something.
The material used in the construction is unsusceptible to corrosion.
Unsusceptible → It is formed from "un-" (meaning not) and "susceptible" (from Latin "susceptibilis", meaning able to receive or undergo). The word "unsusceptible" means not able to be influenced or affected by something.
Think of 'not' ('un-') being able to be 'influenced' ('susceptible') — that's why unsusceptible means not able to be influenced.