Definition of "coz"

Content thee, gentle coz, let him alone.

c. 1591–1595 (date written), William Shakespeare, “The Tragedie of Romeo and Ivliet”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene v]

"I do not expect that, coz; nor do I desire it."

1844, Elizabeth Oakes Smith, "The Love Quarrel", in The Columbian Magazine Vol 1. Issue 1. page 6, col. 2, New York, Israel Post, ed John Inman