Big Bertha is a term that is commonly used to refer to any large and powerful weapon, particularly guns or cannons. However, there are several synonyms that can be used to describe the same kind of weapon systems. Among the most popular ones are 'heavy artillery', 'massive ordnance', 'siege guns', 'big guns', and 'large bore guns'. Each of these synonyms is intimately associated with weapons that are used for long-range warfare and is capable of causing significant damage to targets, whether they are buildings, vehicles, or other forms of infrastructure. Therefore, these synonyms can be used interchangeably to indicate the same concept of a large and powerful weapon.