However, depending on the context, other words can also be used:
* σύμμαχος (symmachos) - "ally"
* συνεργός (synergos) - "collaborator"
* γνωστός (gnostis) - "acquaintance"
It's important to note that the meaning of "friend" in Greek, as in any language, can have different nuances depending on the situation and the specific relationship.