suru verb (irregular), transitive verb
make the same; have the same; be of the same
Used to express that two or more things share a common attribute, state, or quality. Often appears in patterns like ～を同じくする (make something the same) or ～が同じくする (be the same).
両者は意見を同じくしている。
Both parties share the same opinion.
彼らは目的を同じくして協力
They cooperated with a shared purpose.