late 14c., "rule, control," from Old French dominacion (12c.) "domination, rule, power," from Latin dominationem (nominative dominatio), noun of action from past participle stem of dominari "to rule, have dominion over," from dominus "lord, master," literally "master of the house," from domus "home" (see domestic) + -nus, suffix denoting ownership or relation. Sexual sense by 1961.