A "cognate" refers to words in different languages that have a common origin or root. For example, the English word "mother" and the Spanish word "madre" are cognates because they both trace back to the same ancient language. Cognates often share similar meanings and pronunciations, making them easier to recognize for language learners. Cognates can also exist within the same language, where different forms of a word share a common root. For instance, the words "educate," "education," and "educator" are cognates derived from the same Latin root, educare. Understanding cognates can enhance vocabulary and comprehension in language studies.