Cognition: The mental process of acquiring knowledge and understanding through thought, experience, and the senses.
Cognize: To become aware of; to know.
Cognizant: Having knowledge or awareness.
Cognoscenti: People who are experts in a particular field or area of knowledge.
Cognate: Having a common origin; related.
Cogitation: The act of thinking deeply; meditation.
Incognito: Having one's identity concealed.
Recognize: To identify someone or something as previously known.
Reconnaissance: A preliminary survey or inspection, especially of an area of potential military operations.
Cogwheel: A toothed wheel that meshes with another toothed wheel to transmit motion.
Let me know if you'd like more words or examples!