sundoulos designates someone who stands alongside another as a shared slave or servant, in household relations or service to the Lord.

The term consistently marks a person in relation to another as sharing the same slave or servant status. It is used of peers within a household setting, of named workers described in relation to Christ or the Lord, and of a speaker identifying himself alongside those addressed.

1. A person sharing another's slave or servant status · dominant

   In Matthew 18:28, the genitive plural form identifies the man found by the slave as one of his peers; in Matthew 18:29, the nominative singular form identifies the pleading man in the same relationship, and Matthew 18:31 uses the nominative plural for those who witness and report the event. In Colossians 1:7 and Colossians 4:7, singular forms designate named people in connection with Christ or the Lord; in Revelation 19:10, the nominative singular form identifies the speaker alongside the addressee and the addressee's brothers.

   Matthew 18:28Matthew 18:29Matthew 18:31Colossians 1:7Colossians 4:7Revelation 19:10

In the Anselm Project Bible: The APB commonly presents the term as “fellow slave” in the Matthew and Colossians clauses, while Revelation 19:10, Revelation 22:9, and Revelation 6:11 use “fellow servant” or “fellow servants.” These renderings reflect the verses' shared-status relation, but the translation does not align English words token by token.