The phrase "colossus of knowledge" is often used to describe someone who possesses a vast amount of knowledge on various subjects. However, there are numerous synonyms that can be used to describe such a person. They can be referred to as a "walking encyclopedia," a "font of wisdom," or a "fountain of knowledge." They can also be called an "oracle," a "savant," a "polymath," or a "mastermind." Other synonyms include "intellectual giant," "erudite scholar," or simply a "genius." Regardless of the word used, someone referred to as a "colossus of knowledge" is sure to be highly respected and admired for their immense intellect.