This is the 2041st most frequent Russian word.
александром
The word "александром" is the instrumental case of the Russian male name "Александр," meaning "by/with Alexander."
In this sentence, 'Александра' is used as the name in the accusative case, as it is the direct object of the verb 'видел' (saw).
Я видел Александра на вечеринке с другом.
I saw Alexander at the party with a friend.
Here, 'Александром' is used in the instrumental case, showing that the discussion was done 'with Alexander'.
Мы обсуждали проект с Александром.
We discussed the project with Alexander.
'Александром' is again in the instrumental case, indicating that the meeting happened 'with Alexander'.