The word "defender" refers to someone who protects or supports someone or something. Its antonyms are words that have the opposite meaning. These include "attacker," "opponent," "opposer," "adversary," "foe," "antagonist," and "enemy." These words describe someone who is against or hostile towards someone or something. Another set of antonyms for "defender" would be "abandoner," "forsaker," and "betrayer," which describe someone who abandons or betrays those they were supposed to protect. Knowing the antonyms of a word can help us understand its meaning better and enhance our language skills.