Affirm/əˈfɜːrm/ Definition 1 of 4Pro Tip 1/3Objective Confidence Use 'affirm' when expressing certainty about facts or beliefs in an objective manner. Experts affirmed the vaccine's effectiveness. Pro Tip 2/3Emotionally Neutral 'Affirm' is emotionally neutral, without excitement, anger, or other strong feelings. The witness affirmed seeing the suspect leave the scene. Pro Tip 3/3Subtle Confirmation Use 'affirm' to subtly reinforce or confirm a point already made. He affirmed my point, adding credibility to the argument.