The antonyms for the phrase, "act in place of," include words such as neglect, ignore, abandon, negate, and dismiss. Neglect implies disregard or inattention to the task at hand, making it an opposite of taking action in a situation. Ignoring the situation altogether also means not acting in place of. Likewise, abandoning a situation means withdrawing from it entirely, leaving it to resolve on its own. To negate a situation implies actively working against it rather than acting in its place, while dismissing a problem involves writing it off as unimportant. All of these words represent a lack of action and contrast with the original phrase's intended meaning.