There are several synonyms for the word "resistant", which means the ability to withstand or oppose something. These synonyms include "immune", which refers to being protected from something or not affected by it. Another synonym is "impervious", meaning unable to be penetrated or affected by something. "Tough" is also a potential synonym, indicating a strong or resilient resistance. "Sturdy" can be used to describe something that is able to withstand force or strain. Finally, "tenacious" can be a synonym for resistant, indicating a strong ability to persist or hold firm in the face of opposition.