The word "big-wig" generally refers to a person who holds significant power or status, often in a company or social setting. Its antonyms would therefore be terms that connote humility, insignificance, or lack of power. Some antonyms for "big-wig" might include "commoner," "nobody," "peasant," "plebeian," "underling," "inferior," "trainee," "rookie," "junior," "subordinate," "minor," or "lowly." These words can help convey a sense of subservience or lack of importance, which is the opposite of what "big-wig" suggests. It's important to consider the context in which these antonyms might be used, as some can be more appropriate than others depending on the situation.