When someone says they wouldn't lift a finger to help with a task, it means they refuse to do anything to assist. However, several synonyms can be used to convey a similar message should the phrase feel overused. For instance, instead of saying someone wouldn't lift a finger, one can opt to say they wouldn't raise a hand or budge a muscle. One could also say they refused to lift a hand, make any effort, or even move a muscle. These synonyms help to add variety to a commonly used phrase and show more creativity and inventiveness in language usage.