Definition of “resistant” - Learner’s Dictionary

resistant

adjective uk us /rɪˈzɪstənt/
NOT ACCEPTING

not wanting to accept something, especially changes or new ideas:

They're resistant to change.
NOT AFFECTED

not harmed or affected by something:

a water-resistant cover
Bacteria can become resistant to antibiotics.

(Definition of “resistant” from the Cambridge Learner's Dictionary © Cambridge University Press)