This is the 9777th most frequent Russian word.
эрдоганом
"Эрдоганом" is the instrumental case of "Эрдоган," the Russian transliteration of the surname Erdoğan, referring to the Turkish leader Recep Tayyip Erdoğan. It means "with Erdoğan" or "by Erdoğan."
The word 'Эрдоганом' (Erdogan) serves as the instrumental case form of a proper noun, indicating the means or agent of the action (meeting with).
Сегодня я встретился с Эрдоганом на официальной встрече.
Today I met with Erdogan at the official meeting.
Here, 'Эрдоганом' functions in the instrumental case, describing involvement or participation (with Erdogan in the discussion).
Мы продолжили обсуждение новой экономической стратегии с Эрдоганом.
We continued discussing the new economic strategy with Erdogan.
In this usage, 'Эрдоганом' in the instrumental case illustrates the entity that is linked with the event (signing the treaty by Erdogan).