gynarchy (n.)

"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.