Noesis is a term that is used to describe a person's ability to gain knowledge through various means. There are several synonyms for the word noesis, including cognition, understanding, perception, and apprehension. Cognition refers to a person's ability to think, understand, and process information. Understanding refers to a person's ability to comprehend or grasp the meaning of something. Perception refers to a person's awareness of their surroundings and their ability to interpret the information they receive. Apprehension refers to a person's ability to understand or grasp the significance of something. No matter what synonym is used, they all relate to the human ability to acquire and understand knowledge and information.