ο φίλος τον φίλον εν πόνοις και κινδύνοις ου λείπει → a friend does not abandon his friend in difficulties and in danger, a friend in need is a friend indeed
ἀπευθής, ἄγνωστος, ἀγνοητός, ἄβακτος, ἄβυκτος, ἀνέκπυστος