Abaci is a term that refers to a type of ancient calculator that is used to perform arithmetic calculations. This term has several synonyms that can be used to refer to the same thing. In English, the most common synonyms for abaci are 'abacus,' 'counting frame,' and 'calculating frame.' These synonyms are used interchangeably to represent the same object. Other synonyms that are less commonly used include 'reckoner,' 'comptometer,' and 'arithmometer.' The use of these synonyms adds variety and flair to language and helps to avoid redundant expressions. Additionally, it enables individuals to understand complex terms without struggling with unfamiliar vocabulary.