In ancient Rome, slaves were referred to as "masters" or "owners," particularly of slaves. Also, some free men were called dominii because they held power over others by right of dominion (i.e., ownership). Finally, some words in English have dual meanings depending on their context. For example, "dominus" can mean either "master" or "lord." Because slavery existed in ancient Rome, so too did masters and lords. The word "dominus" has two different but related meanings in ancient Roman culture: one refers to a slave and the other to a lord or master. A dominus was any slave who owned another human being and therefore had authority over them. Sometimes this authority was merely implied rather than explicitly granted, but it could also be formally conferred by an owner. For example, a dominus could be created by a parent for their child. Or, two people could become dominii over someone else if that person was given up for sale and then purchased by these two individuals. In addition to slaves, some free men in ancient Rome also served as dominii over others. These were usually very important people who held power over many slaves or other members of their community.