Green’s Dictionary of Slang

a position of sexual intercourse in which the woman is on top of the man.

c.1698		B.E. Dict. Canting Crew n.p.: The dragon upon St. George c. the Woman uppermost.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].