This is the 11441st most frequent Polish word.
irańskim
"Irańskim" means "Iranian" (adjective, relating to Iran).
In this sentence, 'irańskim' serves as an adjective in instrumental case, describing 'samolotem' (airplane).
Podróżowałem irańskim samolotem z Teheranu.
I traveled on an Iranian airplane from Tehran.
Here, 'irańskim' is an adjective in instrumental case, qualifying 'dyplomatą' (diplomat).
Rozmawiałem z irańskim dyplomatą na konferencji.
I spoke with an Iranian diplomat at the conference.
Here, 'irańskim' is used as an adjective in instrumental case, modifying 'sklep' (shop).