Merriam-Webster Collegiate Dictionary - cognate

 I. adjective  Etymology: Latin cognatus, from co- + gnatus, natus, past participle of nasci to be born; akin to Latin gignere to beget — more at kin  Date: circa 1645  1. of the same or similar nature ; generically alike  2. related by blood; also related on the mother's side  3.  a. related by descent from the same ancestral language  b. of a word or morpheme related by derivation, borrowing, or descent  c. of a substantive related to a verb usually by derivation and serving as its object to reinforce the meaning  • ~ly adverb  II. noun  Date: 1754 one that is ~ with another