Brain box is a colloquial term used to describe someone who is intelligent or knowledgeable. There are many synonyms for this term, depending on the context of use. Intellectual, genius, brainiac, clever clogs, smart aleck, and know-it-all are a few examples. These words are all used to describe someone who possesses a great deal of knowledge or intelligence. Some of these synonyms are used in a positive light, while others imply arrogance or overconfidence. It is important to consider the tone and context of the conversation in order to select the most appropriate synonym to use in place of "brain box".