isopsuchos describes the sole person Paul presents as genuinely concerned for the Philippians.

The attested use describes a person whom Paul identifies as uniquely sharing a genuine concern for the Philippians.

1. Sharing genuine concern for others · dominant

   In Philippians 2:20, the accusative singular masculine form describes the one person Paul says will be genuinely concerned for the Philippians; the APB renders the clause, "For I have no one else like-minded who will genuinely be concerned for you."

   Philippians 2:20

In the Anselm Project Bible: In Philippians 2:20, the APB presents the person as "like-minded" and genuinely concerned.