The phrase "have brain" refers to the ability to think and make decisions. Synonyms for this term include "possess intelligence," "display cognitive skills," "employ mental faculties," and "demonstrate mental acuity." Other words that can be used in place of "have brain" are "use reasoning abilities," "utilize critical thinking," "exhibit analytical prowess," and "demonstrate acumen." These synonyms can be interchanged depending on the context and formality of the situation. They all imply that the person in question is capable of rational thought and problem-solving, and is able to make informed decisions based on their mental capacity and intellect.