"government by women or a woman," 1570s, from Greek gynē "woman, wife" (from PIE root *gwen- "woman") + -arkhē "rule" (verbal noun of arkhein "to be the first," hence "to rule;" see archon). Synonymous gynaecocracy (from Greek gynaikokratia) and gyneocracy are attested from 1610s; gynocracy is from 1728.
also gynaecology, "science of women's health and of the diseases peculiar to women," 1847, from French gynécologie, from Latinized form of Greek gynaiko-, combining form of gynē "woman, female," from PIE root *gwen- "woman." Second element is from French -logie "study of," from Greek (see -logy). Another word for it was gyniatrics.