What is the gender of slave and its opposite gender?

The word "slave" is a noun and does not have a gender. It refers to a person who is forced to work for another without pay.

The concept of slavery is not based on gender, and there is no opposite gender for the word "slave."

It's important to remember that using language that reinforces the idea of a "gendered" slave can perpetuate harmful stereotypes and dehumanize people who have been enslaved.