Antonyms for the term "more heart struck" can include a range of words like calm, indifferent, impassive, detached, unemotional, and unaffected. Some other antonyms could be stoic, phlegmatic, dispassionate, composed, apathetic, or cold-hearted. Each of these antonyms denotes a lack of emotional vulnerability or a subdued approach to feelings that contrasts the intensity of the original term. By using these antonyms in place of "more heart struck," the speaker or writer can evoke a different emotional state or convey a lack of emotional response altogether. The choice of antonym depends on the desired effect, tone, and meaning of the overall context.