Cognate \KOG-neyt\ , adjective;
1. Related by birth; of the same parentage, descent, etc.
2. Linguistics: Descended from the same language or form
3. Allied or similar in nature or quality
1. A person or thing cognate with another
2. A cognate word
Cognate is very common in historical linguistics, perhaps for obvious reasons. The word itself dates to the 1640's from Latin cognatus ("of common descent"), which is a combination of com- + gnatus ("toether" + "to be born"). Gnatus is the past participle of gnasci, which is the older form of nasci from Proto-Indo-European *gen-/*gon-/*gn- ("produce, beget, be born"). The noun version is first attested in 1754.