The word "heavyweights" can be used to describe influential or powerful people or entities. When looking for alternatives to this term, one might consider using "titans," "giants," "moguls," or even "tycoons." These words all convey a sense of great significance and substantial impact in their respective fields. Other possibilities include "powerhouses," "leaders," or "bigwigs." All of these words can be used to describe individuals or organizations that are capable of making a significant impact or leaving a lasting impression. Choosing the right synonym will depend on the context and tone of the message being conveyed.