The term "betray" refers to deceiving or breaking the trust of someone. Its antonym can include words like support, assist, defend, follow, unite, and uphold. These antonyms encapsulate the exact opposite of betray, implying that one is standing with someone and supporting them in their endeavors rather than betraying them for personal gains. For instance, supporting someone means that one is standing with them through thick and thin and motivating them to do better, while betraying them would merely mean pulling them down and causing harm. The choice of using antonyms for "betray" extremely depends on the context of the sentence in question.