The phrase "more aback" can be replaced with a variety of synonyms to convey a similar meaning. These synonyms include "more surprised," "more taken aback," "more shocked," "more startled," and "more stunned." Each of these phrases emphasizes the level of surprise or shock that a person experiences in a given situation. Using synonyms can help to add variety and nuance to your writing, allowing you to communicate your ideas more effectively. Whether you're writing a novel, an essay, or a news article, incorporating synonyms for "more aback" can make your writing more engaging and impactful.