douloo describes being brought under a master or controlling power, whether imposed, chosen, or attached to an abstract object.

The attested usage most often describes persons as brought under a binding master, power, or object: corruption, righteousness, God, much wine, or a relationship described as being bound. It also describes deliberately making oneself a slave to others and the future act of enslaving others.

1. Being under a binding power or attachment · dominant

   Passive forms describe persons as under an attachment or controlling object. In 1 Corinthians 7:15 the APB renders the clause “the brother or sister is not bound”; in 2 Peter 2:19 it says that a person is “enslaved” by what overcomes him. Romans 6:18, Romans 6:22, and Titus 2:3 likewise place the passive forms with righteousness, God, and much wine.

   1 Corinthians 7:152 Peter 2:19Romans 6:18Romans 6:22Titus 2:3
2. Choosing to make oneself a slave to others · occasional

   In 1 Corinthians 9:19, the first-person aorist active form occurs after “I am free from all”; the APB renders the resulting action, “I have made myself a slave to all,” with the stated aim of gaining more.

   1 Corinthians 9:19
3. Enslaving others by imposed action · occasional

   In Acts 7:6, the future active plural form refers to those in another land acting upon the offspring; the APB renders that they “would enslave them and mistreat them.”

   Acts 7:6

In the Anselm Project Bible: The APB variously uses “bound,” “enslaved,” “made myself a slave,” and “would enslave” in these verses. Because the APB is a whole-verse translation, these renderings show the clauses' presentation rather than a fixed English equivalent.